High Performance Thermal Insulation Systems Vacuum Insulated Products...

International Energy Agency

Energy Conservation in Buildingsand Community Systems Programme

High Performance Thermal Insulation Systems

Vacuum InsulatedProducts (VIP)

Proceedings of the International Conference and Workshop

EMPA Duebendorf, January 22-24, 2001

Edited by:Mark Zimmermann, Hans BertschingerSwiss Federal Laboratories for Materials Testing and ResearchCentre for Energy and Sustainability in Buildings

High Performance Thermal Insulation (HiPTI) – Vacuum Insulated Products (VIP),

EMPA, January 22–24, 2001

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International Energy Agency

Energy Conservation in Buildingsand Community Systems Programme

High Performance Thermal Insulation Systems

Vacuum InsulatedProducts (VIP)

Proceedings of the International Conference and Workshop

EMPA Duebendorf, January 22-24, 2001

Edited by:Mark Zimmermann, Hans BertschingerSwiss Federal Laboratories for Materials Testing and ResearchCentre for Energy and Sustainability in Buildings [email protected]@empa.ch



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Table of content

High Performance Thermal Insulation Systems (HiPTI)Vacuum Insulated Products (VIP)

Conference Presentations, Monday, January 22, 2001 Page

Introduction Mark Zimmermann (EMPA) 5

The role of High Performance Insulationin energy efficiency –Overview of available technologies Prof. Dr. Hanspeter Eicher (E+P) 9

Physical aspects of heat transfer and thedevelopment of thermal insulation Prof. Dr. Jochen Fricke (ZAE) 13

State of the art of glazing technologies –High performance and vacuum glazing Volker Herrmann (Glas Troesch) 23

Vacuum insulated products with fumed silicaProduction, properties and applications

Applications of VIP's in technical building systems(HVAC, solar and hot water systems, storage tanks) Dr. Peter Randel (Wacker GmbH) 27

NanogelsProduction, properties and applications Franz-Josef Pötter (Cabot Corp.) 33

VIP packaging materials and technologies Dr. Gerald Levebre (LMN) 37

Measurement of physical properties Dr. Hans Simmler (EMPA) 47

VIP for advanced retrofit solutions for buildings Dr. Ralf Materna (ZZ Wancor) 55

Existing and future applications for advancedlow energy building Dr. Wolfgang Feist (Passivhaus-Institut) 63

VIP's for buildings – Research and DevelopmentPresentation of goal, project structure andorganisation of IEA R+D-programme Markus Erb (E+P) 71

Workshop Presentations, Tuesday, January 23, 2001

Workshop Programme 81

Annex 39 High Performance Thermal Insulation (HiPTI) draft 83

Preliminary study on High Performance ThermalInsulation Materials with gastight porosity Dr. Monika Damani (EMPA) 95

Flexible pipes with High PerformanceThermal Insulation Robert Weber (EMPA) 99

Evaluation of modern insulation systemsby simulation methods Prof. Dr. Jürgen Dreyer (TU Wien) 101

Development of vacuum insulation panel P. Hoogendoorn (LEVEL energy technology, NL) 107

with stainless steel envelope



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page

Workshop on HiPTI (Annex 39: )

Proceedings of the workshop 113

Conclusion of the working groups 115

Next steps 121

Appendix 122

Conference speakers 123

Workshop participants 124

List of participants (conference and workshop) 127

High Performance Thermal Insulations (HiPTI) – Vacuum Insulated Products (VIP),


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Introduction

Mark ZimmermannEMPA ZENÜberlandstrasse 1296000 Dübendorf

In energy technology, the last century was the century of thermal insulation. Most insulationmaterials have been developed before 1950 but the extensive use of thermal insulation startedonly after the oil crisis. First building envelopes were insulated in the sixties and used layers about3 cm cork to prevent condensation. Since the oil crisis, the thermal insulation of buildings becamethe key element to prevent heat losses and to improve energy efficiency. For a long time, 10 cm ofinsulation were considered as good insulation. But energy specialists calculated that theeconomically optimised thickness should be 50 cm and more.

Today, many existing building laws and standards demand U-values for roofs and walls of around0.2 W/(m2·K) which means insulation layers of about 20 cm. Many architects have a problem withsuch regulations. They want to create spaces, not insulated bunkers. And for many applications,for retrofit, for technical installations and for appliances thick insulation layers are often notappropriate. The extra costs for adaptation or for space loss are often high and would justify amore expensive, more efficient insulation material.

Whereas glazing systems have been substantially improved during the last decade, opaqueinsulation has remained relatively unchanged. The best available glazings achieve a thermalconductivity of 0.009 W/(m·K) (U-value of 0.35 W/(m2·K) at a thickness of 23 mm). This is achievedby applying low-e coatings and special gas fillings.

On the other hand, traditional insulation uses air as the isolator. Thus the thermal conductivity of airat 0.025 W/(m·K) sets the limit of performance for such material.

To overcome this, new techniques are being developed based on the following technologies:

• microporous structures,

• vacuum technologies,

• special gas fillings.

First applications have proven that such insulation techniques can achieve a thermal conductivityof about 0.005 W/(mÂ.��WKXV�SHUPLWWLQJ�LQVXODWLRQ�OD\HUV�RI��WR��WLPHV�WKLQQHU�WKDQ�FRQYHQWLRQDOinsulation materials.



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Market studies have shown a vast potential for the application of these high performance insulationtechniques. Such insulation layers have already been shown to be effective, especially in the areasof:

• appliances such as refrigerators, deep freezers, stoves, storage

• tanks and transport containers,

• heaters, chimneys, and pipe work,

• façade elements and light weight construction, and

• internal insulation of walls.

Current demonstration applications are mainly based on microporous, evacuated and sealedinsulation materials. These have proven good performance, but they have also shown the need forfurther industrial development.

Therefore, the Energy Conservation in Buildings and Community Systems Programme of theInternational Energy Agency (IEA) has decided to start a research and development programmeon High Performance Thermal Insulation Materials (Annex 39).High Performance Thermal Insulation in BuildingsThere will be an initial one year preparation phase beginning in January 2001. The workshopfollowing this conference will be the «Kick-Off Meeting» for all interested Annex participants.Currently, representatives from Austria, Belgium, Canada, Denmark, France, Germany, Italy,Netherlands, Sweden and Switzerland have expressed an interest in taking part in thiscollaborative research. In addition, Switzerland has offered to take on the role of lead country.

It is envisaged that this Annex will concentrate on insulation materials and systems with a thermalconductivity of less than 0.015 W/(m·K). Presently, only vacuum technologies, preferably incombination with microporous structures, achieve this performance. Therefore Vacuum InsulatedProducts (VIPs) and their applications will form the basis of investigation.

Four Subtasks are proposed:

Subtask A: Basic concepts and materials

• New concepts for HiPTI will be examined and evaluated. Suitable concepts will then beimplemented as prototypes. Also, existing products will be analysed and their heat conductivity,life span and cost characteristics will be optimised. This will include support structures of HiPTI,possible package films and gutter materials for extending product life span. Quality monitoringwill be examined in addition.

Subtask B: Application and system development

• In cooperation with the building industry, existing and new insulation materials will be furtherdeveloped into useable construction systems.

Subtask C: Demonstration

• Applications of HiPTIs will be demonstrated and performance data collected. Practicalexperience will also influence the development and improvement of construction systems.Furthermore, construction personnel will be trained in the correct use of HiPTIs.



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Subtask D: Dissemination• Strategies to address and inform opinion leaders and manufacturers, as well as construction

companies and their clients, will be developed. Taking the experience from the demonstrationprojects into account, appropriate information material and application guidance will beproduced and distributed.

This conference will give an introduction and a state of the art survey of these techniques and willinform participants of planned research work.

The goal is start an new initiative to investigate new options for high performance thermalinsulation systems, to improve their quality and the knowledge for a successful application. It is notthe intention to replace conventional and well known insulation materials and technologies. HighPerformance Insulation should became an new and attractive option for special application whereavailable space is limited or extra costs for thick layers would be high.



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EMPA, January 22 - 24, 2001

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The role of High Performance Insulation in energy efficiency

Hanspeter EicherDr. Eicher + Pauli AGKasernenstrasse [email protected]

SummaryIn the last twenty years thermal insulation standards for buildings and technical equipment hasrisen considerably. In the same period, windows technology has been improved in parallel, whichis not the case for conventional opaque thermal insulation. This led to the astonishing situation,that in today's windows technology, the thermal conductivity is two times smaller than in anordinary thermal insulation. (0.02 W/(m2Â.��YHUVXV��:��P2Â.��

As a consequence, thermal insulation thickness of building envelopment has risen from 0.02 m to0.15 m for ordinary new houses and to 0.35 m for very low energy houses e.g. with passivestandard. In such a house, more than 30 % of the volume is used by the insulation. New vacuuminsulation panels have thermal conductivity values, which are ten times smaller (0.004 W/(m2Â.�instead of 0.04 W/(m2Â.��WKDQ�LQ�FRQYHQWLRQDO�LQVXODWLRQ�PDWHULDOV��$OUHDG\�WRGD\�WKH�QHW�VSDFHgain can led to an economical use of this materials in new buildings.In the retrofit sector there are many buildings which will allow only small insulation thicknessbecause otherwise to much room space or height is lost or the adaptation of many constructiondetails is simply to expensive when using high insulation thickness. This means that a greatnumber of existing buildings only with HiPTI can match today's and future demand for thermalinsulation.As the future of HiPTI seems great which such an outlook, much work needs to be done, todevelop today's vacuum insulation to proven and reliable construction systems to fulfil customersdemands.



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1. Structure of High Performance Insulation (VIP in this case)

Figure 1:Principle elements of a vacuum insulation panel (VIP)

Fumed silica and aerogels are the most widely proposed micro porous materials for VIP. Fumedsilica is an industrially produced material, which has been optimised for vacuum insulation in thelast years, it even don’t need any getter when the gas barrier foil is intact. Progress is stillnecessary and possible in the field of gas and vapour barriers.

2. Thermal conductivity of VIP

0

5

10

15

20

25

30

35

40

0.001 0.01 0.1 1 10 100 1000

Gasdruck pGas [mbar]

Wär

mel

eitfä

higk

eit

λ [m

W/(

mK

)]

Kieselsäure (Wacker WDS)

offenzelliges XPS (INSTILL)

offenzelliges PUR

Glasfasern

Figure 2: Heat conduction of different types of VIP in function of gas pressure

Up to now, fumed silica and aerogels, which should have roughly the same thermal properties, arethe best-suited materials for the use in buildings. They have a very low thermal conductivity whichremained constant up to 20 mbar, they do nut burn and have interesting acoustic properties.

GetterMicro porous corematerial

Gas andvapor barrier

Vacuum from 0.1 to20 mbar



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3. Economical aspects

Ground costIn a low energy house (passive standard), the insulation volume is about 30 % of the buildingvolume. By a given allowed site exploitation, the needed ground surface will increase accordingly.When using VIP or other High Performance Insulation (HiPTI), it is possible to save costs, whileoffering to the customer the same usable area (room and garden).

Gaining usable floor spaceWith a given site surface, normally it will be possible to let more room space when using lessinsulation thickness. Assuming a flat of 100m2 which cant be let for CHF 1700.-/month, the value ofgained space is about CFH 3'400.-/m2, in order to get a yield of 6 %, related to the invested capital.(12Â��Â��:LWK�WKH�VSDFH�JDLQHG�\RX�FDQ�FDOFXODWH�WKH�PD[LPXP�SULFH�IRU�DQ�P3 ofHiPTI. Figure 3 shows admissible insulation cost in function of the value of space that has beengained.

Surface to let (100m2 , 1700 CHF/Mt

Construction costs

Ground

0

500

1000

1500

2000

2500

3000

3500

0 2000 4000 6000 8000

Surface costs [CHF/m2]

Admissible cost for HiPTI [CFH/m3]

Figure 3: Admissible costs per m3 for HiPTI in function of the value of the saved usable floor space.Conditions: thickness of thermal insulation 2.5 instead 12 cm, room height 2.6 m, 200.- CFH/m3 for ordinarythermal insulation

4. HiPTI in new buildingsThe above calculation shows, that HiPTI in new building can be of great economical interestbecause of saving ground space, or even better, to rent more room space with a given area of theconstruction site. Therefore HiPTI should be considered in every project for a new building.



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5. HiPTI in existing buildingsIn the case of existing buildings the situation is more complex. In many cases it is possible to useexterior wall insulation without loosing floor space or without the need of having a bigger buildingsite. Therefore in retrofit, HiPTI is only economically interesting, when insulation leads to the looseof floor space, room height or if the adaptation costs would be to high when using conventionalmaterials. The following cases are of interest:

Figure 4: Interesting HiPTI application in retrofit

6. Is HiPTI ready for the building market?Obviously it is not; otherwise we would not be here today. What must be done in the next fewyears?

Basic materials and conceptsImprove existing products; ensure mainly durability and lifetime

Systems and applicationsDevelop complete systems that are usable in the common building business (e.g. VIP floor heatingsystems, high insulated boilers, interior wall insulation systems ...)

Demonstration projectsImprove know-how of building professionals. Demonstrate the use of available VIP and other HiPTIsystems in real applications

LiteratureHp. Eicher, M. Erb, A. Binz; Hochleistungswärmedämmungen, Bericht BFE, Dezember 2000

Terrace

Floor heating

Hot waterequipment (onlynew)

Interior wall

Outer door

High High Performance Thermal Insulations (HiPTI) – Vaccum Insulated Products (VIP),


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Physical Aspects of Heat Transfer and the Development of ThermalInsulations

Jochen FrickeUniversität Würzburg andBayerisches Zentrum f. Angewandte Energieforschung e. V. (ZAE Bayern)Am HublandD-97074 Wü[email protected]

Summary

Thermal transport in insulations with its three modes, solid conduction, gaseous conduction andinfrared-radiative heat transfer is described and discussed. As an example for conventionalinsulants thermal transport in EPS foams is explained. Heat transfer in aerogels serves as anexample for nanostructured insulation materials. Evacuated nanoporous thermal insulationsprovide the lowest possible conductivities (about 0.003 to 0.004 Wm-1 K-1) and thus the largestthermal resistance for load-bearing insulants. They are most tolerant against pressure increase.The anticipated lifetime for optimized vacuum insulation panels ist large enough to allow for theirapplication in buildings. Finally switchable thermal insulations are described, which are well suitedto harvest solar thermal energy for heating purposes.



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1. Introduction

Conventional insulants, as fibers, powders or foams suppress convection, which is due tothe partition of the insulating spacing into sub-mm cells or pores. Typically the thermalconductivity λ is in the range 0.035 to 0.060 Wm-1 K-1 (see figure 1). Such insulants, tosome extent, also reduce radiative transfer via absorption and/or scattering of infaredradiation. At room temperature the radiative conductivity λr may vary in the range 0.001 to0.010 Wm-1 K-1. Contrary to just air-filled or evacuated spacings solid insulating materialscause transport via solid conduction. The corresponding conductivity λs is the smaller, thelower the density of the insulant becomes and the smaller the conductivity of the fibers, thepowder grains or the foam backbone is. λs varies between 0.001 and 0.030 Wm-1 K-1.

Fully developed in conventional insulants is the gaseous conduction; this heat transfermode mostly is the dominating one, adding λg ≈ 0.025 Wm-1 K-1at room temperature to thetotal conductivity.

In general the three conductivities λr , λs and λg are non additive: coupling or bridgingeffects tend to increase the total conductivity beyond the mere sum, i. e.:

λ > λr + λs + λg.

For example, in powder fills with many point-like contacts the conduction in the gas phasethermally bidges the point contacts and leads to dramatic coupling effect; contrary, infoams and aerogels with a coherent solid skeleton the coupling effect between solid andgaseous thermal conduction ist negligible. In this case

λ ≈ λr + λs + λg

holds.

The systematic improvement of thermal insulation was studied and described in apioneering work in the nineteen sixties by M. G. Kaganer [1].



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2. Conventional Insulants

As an example let us consider the thermal conductivity of EPS or styrofoam(figure 2):

The gaseous conductivity λg is more or less independent of density (it only shows a smalldecrease at higher density, which is caused by the decreasing pore volume). The solidconductivity increases roughly proportional to the density. For foams with ρ ≈ 15 kg m-3

one gets λs ≈ 0.001 Wm-1 K-1.

As the thermal radiation for most insulants (more exactly: optically thick ones) ispropagating via diffusion, a simple dependence for λr holds:

λr ~ T 3/E,

where E is the extinction coefficient ([E] = 1/m), and T the temperature.

Furthermore

E = 1/O = ρ e,

with O being the mean free path of the IR photons and e being the mass specific extinction.For a value e ≈ 100 m2 kg-1 and for ρ ≈ 15 kg m-3 one gets E ≈ 1500 m-1 or O ≈ 0.6 mm.

From the above equations we derive that λr ∼ 1/ρ. For ρ ≈ 15kg m-3 EPS foams one gets

λr ≈ 0.011 Wm-1 K-1.

The total conductivity for EPS foams with ρ ≈ 15 kg m-3 thus is

λ ≈ λg + λs + λr = (0.025 + 0.001 + 0.011) Wm-1 K-1

= 0.037 Wm-1 K-1.

If a few weight percent of an opacifier, e. g. carbon black, silicon carbide or iron oxide areintegrated into the foam, the specific extinction can be increased considerably and theradiative conductivity lowered correspondingly. The total conductivity then can be as lowas 0.032 Wm-1 K-1. Such EPS-foams are grey instead of white.



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3. Nanostructured Insulants

Nanostructured silica insulants can either be made in a flame process or a wet chemicalsol-gel process; the resulting materials are called fumed silica and aerogels [2],respectively. Let us consider thermal transport in aerogels as an example. The solidthermal conductivity here varies according to λs ∼ ρα , with α ≈ 1,5 (see figure 3). Forρ ≈ 150 kg m-3 the solid conductivity is about 0.005 Wm-1 K-1.

The fact that α > 1 can be explained by the many dangling ends (especially for smalldensities) of the tenuous structure which is made up of pearl - string - like entities, while inEPS foams a much more efficient interconnection between the foam cells exists.

For a thickness of about 1 cm the radiative transport is diffusive in the 10 µm wavelengthregion for SiO2 - aerogels but is nearly ballistic in the 3 to 6 µm range. To prevent IRphotons in this wavelength range from being transferred directly from the hot to the coldbroundary, it is absolutely necessary to add an opacifier to the aerogel. Carbon black is agood choice, the aerogel then has a dark appearance. The radiative conductivity foropacified aerogels is in the 0.001 Wm-1 K-1 range at room temperature.

As the pores in aerogels are about 50 nm, the gaseous conduction is suppressed, even at1 bar. With a mean free path of 70 nm for air molecules at this pressure the Knudsennumber (mean free path divided by cell size) is of the order of 1. The air molecules collideabout as often with each other or with the pearl-strings of the aerogel skeleton. Thus thegaseous thermal conductivity is not 0.025 W-1 K-1as in EPS foams but only 0.005 to 0.010Wm-1 K-1 (see fig. 3).This partial suppression of gaseous conduction at ambient pressuresis typical for nanoporous materials.

The overall conductivity for opacified SiO2 aeorogels at 1 bar is below 0.020 WM-1 K-1; forresorcinol-formaldehyde aerogels a conductivity as low as 0.012 Wm-1 K-1 for a density of150 kg m-3 was measured [3]. Somewhat higher values (0.015 to 0.020 Wm-1 K-1) areobtained for ground aerogel.

4. Evacuated Insulants

The suppression of gaseous conduction occurs, if the Knudsen number becomes muchlarger than 1. For thermoflasks with spacings between the cylindrical walls in the 1 mm to1 cm range a vacuum of below 10-4 mbar is required (figure 4). The atmospheric pressure(10 tons per m2) has to be sustained by the glass or steel walls of the flask. Radiativethermal transport in this case is the only remaining loss mode, which depends on theemissivity of the walls and their temperatures.



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If instead of cylindrical or spherical volumes flat panels are to be evacuated theatmosphreric pressure load has to be sustained by a load-bearing fill, e. g. a fiber, foam orpowder board. As one learns from figure 4 the requirements for evacuation are the leastfor nanostructured fills. In this case evacuation to 10 mbar is sufficient to eliminategaseous conduction. The material, which is suitable for such an application andcommercially available in large quantities, is fumed silica. The material consists ofagglomerates of SiO2, which are built up of aggregates, which countain primary particles.Mixed with an opacifier the hydrophilic high porosity powder is pressed into boards withdensities in the 100 to 200 kg m-3 range. The thermal conductivity of such a board as afunction of gas pressure is shown in figure 5. Fully evacuated the conductivity is between0.003 and 0.004 Wm-1 K-1. For 40 mbar the conductivity is around 0.005 Wm-1 K-1 and at1bar a conductivity of 0.018 Wm-1 K-1 is measured. Such boards, if evacuated andwrapped in vacuum tight, high barrier foils maintain their low thermal conductivity (λ <0.005 Wm-1 K-1) for years and even for tens of years. They are thus most suitable even forapplications in buildings, where lifetimes of decades are required. In the worst possiblecase, if for example the barrier foil is punctured, the conductivity rises to about 0.018 Wm-1

K-1and thus is still only half as large as for styrofoam boards. Constructive means e. g. aprotective glass covers can eliminate such a worst case.

5. Switchable Thermal Insulation

Birds adapt to the changing temperatures during the year quite well: In summer theirfeather plume is slim, the porosity is small and the bodyheat can be dissipated efficiently;in winter the feathers are turned into a fluffy, highly porous "ball" which reduces the heatloss sufficiently for survival. Another approach is chosen to vary the heat transfer in a flatsteel panel, welded around an evacuated fiber board: a small amount of hydrogen, whichhas a high conductivity, is released by a metal hydride getter upon heating. Thus thethermal conductivity of the panel can be increased from 0.002 to 0.100 Wm-1 K-1 (figure 6).If the getter heater is switched off again, the H2 is readsorbed and the thermal conductivitydrops back to 0.002 Wm-1K-1. Such a device (figure 7) is ideal for solar thermal usage.During night and cloudy winter days the panel remains in the highly insulating state; thisstate is also kept during hot summer days, to avoid overheating. During sunny winter daysthe panel is in the conducting state, allowing heat to flow into the interior of the house.

References

[1] M.G. Kaganer, Thermal Insulations in Cryogenic Engineering, Irael ProgramFor Scientific Translation LTd. (1969)

[2] J. Fricke , Scientific American May 1988, p. 92

[3] X.Lu et al, Science 255,971(1992)



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Figure Captions

1. Overview on different insulation materials

2. Total thermal conductivitiy and its components of a cellular foam as a function ofdensity



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3. Total thermal conductivity ( ■ ), gaseous conductivity ( ● ) solid conductivity ( ▲ ) andradiative conductivity (---) of an opacified SiO2 aerogel versus density

4. Relative thermal conductivity as a function of air pressure, with the pore width as aparameter



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5. Thermal conductivity for a fumed silica board as function of gas pressure

6. Thermal conductivity of a glass fiber board as a function of H2 pressure



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7. Application of switchable insulations for solar thermal usage



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Insulated Glazing / Current Status of Technology

Volker HerrmannGlas Trösch AG HY-TECH-GLASSIndustriestrasse 12, CH-4922 Bö[email protected]

SummaryToday for applications like facades mainly insulated glazing with so called Low-E coatings areused. Coatings produced in Magnetron Sputtering technology deliver the best results withemissivity levels of 3 %. For double insulated glazing with air spacing of 12 mm and krypton gasfilling U-values of 0.9 W/m2K are achieved, while in triple glazing configurations with 2 coatings andtwo 10 mm air spacing filled with krypton gas, U-values of 0.5 W/m2K are achieved. But these dayshighly selective glazing becomes more and more important. These are glazing configurations withcoatings that combine very low emissivity and reduced total energy transmission whilesimultaneously having a high light transmission level.



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Insulated Glazing: Current Status of Technology

Modern Insulated Glazing as a foundation for the whole window

Still in the beginning of the 1980's, windows were thought to be the weakness of a building'sarchitecture. In the meantime, the efforts to improve the U-value of insulated glazing has madedramatic progress. An IG U-value of 0.5 W/m2K is possible now thanks to modern insulated glasstechnologies. Today, the glazing is a highly insulating factor of the building architecture that isalmost as effective, in insulating, as the fixed walls. This glazing has become an important elementto help modern architecture's preference for transparent and abundant natural light.

The Relevant Parameter For The Window U-Value

The insulating capability of modern insulated glazing is, in general, higher than that of the windowframe. An improvement of the window U-value can be achieved by choosing a good insulatingglass as well as optimizing the ratio of IGU area to window frame area. That means big windowsare better than small ones and small frames are better than wide ones.

High Comfort of LivingToday, big windows are not a problem either in terms of energy conservation or in terms ofcomfort. With good insulated glazing not only can the use of energy be dramatically reduced, butcomfort can also be improved. A good insulation tends to make higher surface temperatures on theinterior side of the glazing. The comfort, especially near the window and for big windows, isincreased this way. With additional attention to the insulation of the edge of the glazing, the risk ofhumidity condensation will be reduced to a minimum.

Coatings and Gas-FilingsInsulated coatings are used to reduce the energy radiation which is massive on the glass surface.A pure silver layer is used as the relevant element to reduce the energy radiation. A measure forthe efficiency of the insulated coating is the emission capability of the coated surface, the"emissivity" (ε). The lower the ε-value the better the U-value of the insulated glass element. Foryears, insulated glass has been coated with transparent heat-reflective layers. Ort a global basisthe most advanced coating technology used is: multi-chamber high vacuum magnetron sputtering.In this process, several metal or metal oxide layers with thickness' of a few nanometers aredeposited in an electromagnetic process in a high vacuum. A U-value of 1.0 W/m2K for the glazingis the standard in Switzerland today. This number is achieved by a double glazing with anoptimized magnetron heat-reflective coating and an argon or krypton gas filling (with an air-spaceof 12-20mm.) An optimized heat-reflective coating in this case means a coating which is a littlemore complex and has a slightly thicker silver layer than those heat-reflective coatings that cameto market in the 1980's and are standard today.

ε-values of various Magnetron heat-reflective coatings

• SILVERSTAR W standard-coating (4-layers) ε = 7 %

• SILVERSTAR V optimized coating (6-layers) ε = 4 %

• SILVERSTAR SELEKT heatrefl./sunprot. (9-layers) ε = 3 %

comparison : regular glass (not coated) ε = 84 %



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In general, improving the efficiency of a coating i.e., the reduction of the emission capabilities,causes a lower g-value. On the other hand, with gas-filings the U-value can be reduced onlyslightly but without changing the g-value. The gas-specific optimization of the width of theairspacing of the double glazing plays an important role in the efficiency of the gas filings.

The air-spacings of the double glazing can contain the following gases:

• air

• Argon (Ar)

• Krypton (Kr)

• mixture of Argon and Krypton (Ar/Kr)

The following U-Values can be achieved with Krypton- or Argon/Krypton fillings:

SILVERSTAR V 2x 1.0 W/m2K

SILVERSTAR SELEKT 2x 0.9 W/m2K

SILVERTAR V 3x with 2 coatings 0.5 W/m2K

SILVERSTAR SELEKT 3x with 2 coatings 0.5 W/ m2K

With xenon filings in double glazing 0.8 W/m2K and triple glazing with two coatings even 0.4W/m2K can be achieved. These numbers have only theoretical value. Xenon is a rare gas as well,but is existing only in small percentage points in the atmosphere. The production of xenon gas isonly possible in small amounts and therefore, expensive. In addition, there is not enough xenongas for insulated glazing available.

Double-Insulated Glazing with U-Values Below 1.0 W/m2KEnvironmental awareness and responsible construction demands more and more insulated glazingwith U-values below 1.0 W/m2K . Not in every case, triple glazing elements can be used. Veryoften, construction and insulated glazing technology do not allow their use. In some cases,doubleinsulated glazing with two magnetron coatings and krypton filings are used and U-values of0.8 W/m2K achieved.

U-value (W/M2 K) LT g-value

• SILVERSTAR V II 2x 0.8 69% 46%

• SILVERSTAR SELEKT II 2x 0.8 71% 41%

SILVERSTAR SELEKT: a Special GlassSpace that is designed to use many windows , as modern architecture likes to do, demands a goodinsulating glazing during the heating period. This is the only way to achieve a comfortable interiorclimate and a reasonable level of energy consumption. In the summer and partly in the annualtransition periods rooms behind glass facades can become very warm caused by the greenhouse



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effect. The only way to prevent this is an efficient solar reflective glass. SILVERSTAR SELEKTplays a special rote among the insulated glazes. It's complex coating, consisting of nine individuallayers, not only makes for a high quality insulation but also for an efficient protection against thesun. Compared to other classic solar reflective glazes, the solar energy protection of SILVERSTARSELEKT does not reduce the light transmission. The coating is capable to react differently to solarradiation in different wavelength ranges. Sunlight i.e. radiation in the visible part of the spectrum(between 380 and 780nm) is transmitted while high energy radiation of the solar spectrum (above780nm) will be reflected. The result of this coating technology is a high light transmission level witha low total energy transmission level. This is called "high selectivity." Selectivity means the ratiobetween light transmission level and total energy transmission level.

Selectivity = Light transmission level : Total energy transmission

Selectivity of SILVERSTAR SELEKT = 73% : 41% = 1.78

In reality, high selectivity means a lot of daylight without overheating the interior. This is anadvantage for our modern architecture. Now the question arises: "Can SILVERSTAR SELEKT beused without any further solar reflective application?" Normally, windows which are in the directionof the sun need an additional solar protection, even if they use SILVERSTAR SELEKT. This canbe done by shutters or blinds (or other window coverings) that are used during the high daytimetemperatures and Jong daylight periods in the summertime. The advantage of highly selectiveglazing is not necessarily in substituting conventional sun-protective applications but in reducingtheir usage. But, one must consider that whenever a mechanical sun-protection is used, almost alldaylight as well as the view is lost.



27

Vacuum Insulation Panel with fumed silica

Peter RandelWacker Chemistry87437 [email protected]



28

Core Businesses

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Total sales 1999US$ 2,656 m

Semiconductors

Polymers

Silicones

Materials

Sand



29

Fumed SilicaProduction Process in a Flame

SiO2

SiO2SiO2

SiO2

SiO2BurnerSiCl4 + 2 H2 + O2

SiCl4 + 2 H2 + O2 → SiO2 + 4 HCl

SiO2- proto- primary aggregates agglomeratesmolecules particles particles

Application of Wacker WDS® SIC

automotive industry pipe in pipe

fuel cell vacuum insulation

fire protection appliance industry

Wacker WDS SiC HTWacker WDS SiC NT



30

Comparison of insulation systems

0 10 20 30 40

PS/PU-Foam / MineralFíber

Wacker WDS SiC

PS/PU-Schaum (Vacuum system)

Wacker WDSSiC (Vacuum system) 3 - 3,5 mW/m K

6 - 8 mW/m K

20 mW/m K

35-40 mW/m K

λ vs p



31

hydrogen bonding

Silanol group

WACKER HDK®

Aggregat

10nm

Application

Applications of VIP´s in industrial insulation fields• High Temperature Super Conductor Transformator• HCl Container• Truck container• Facade cladding systems• Automotive industry/Battery Technology• Fuel Cells



32

Roller-mountedcontainers

Interchangeabletruck bodies

Shipping boxes

Tank containers

Trucksuperstructures

Logistics

Façade cladding

Systems engineering

Cold storage cells

Surface heatingsystems

Buildingconstruction

Cooling and freezingequipment

Ovens

Microwave ovens

Domesticappliances

Vacuum-Panel(Vac-Pan)



33

Nanogel™

Production , Properties , Applications

F.-J. PötterCabot GmbHJosef-Bautz-Str. 1563457 Hanau -Germany

IntroductionThe history of aerogels started in 1931 when Kistler made the first aerogels in a supercriticaldrying process . The expensive process and costly rawmaterial like Tetraethoxysilane where theroadblocks for a successful commercial production of aerogels in large industrial scale for morethan a half century .This scenario changed in early 1990ies when new research results from the University of NewMexico generated silica aerogels in a non-supercritical drying process 1).

Easy available and cheap raw material , waterglass and the new low-cost drying processmotivated Hoechst and Cabot to think about a industrial production processes for aerogels .Booth Companies started independent research and commercialisation programs for aerogels.

In 1998 Hoechst sold their aerogel development program to Cabot .Cabot joint both development programs together and two pilot plants in Tuscola/Ilinois andFrankfurt Germany work for process and application development .The next step , a semi-commercial plant will start with a capacity of 10 .000 m³/year Nanogel™aerogels in spring 2002 .

The Industrial Production ProcessThe basic raw material for the Nanogel™ production is waterglass ( sodium silicate ) . Waterglassis a widely used basic rawmaterial for metal casting , mining and the production of precipitatedsilicas .In a polymerisation process under acid conditions the waterglas silica particles are formed to ahydrogel . The side-conditions of the polymerisation like pH , temperature , silicate concentrationand time define the properties of the final aerogel , e.g. density , porosity , strength and surfacearea .The hydrogel is already the final high porous silica particle with pores in the size of 10-20 nm but this pores are filled with water .



34

The direct drying under ambient conditions destroy the pores in the gel and the volume of the gelshrinks by a factor of 5- 10. This shrinkage caused by the capillary forces is irreversible and calledthe collapse of the gel.Shrinkage can be eliminated by supercritical drying , but this drying process under high pressureconditions is seen as to costly for a large scale industrial production of aerogels .

The ambient pressure drying is based on internal surface modification by silation of the wet gel orhydrogel . Gels with hydroxyl groups covered by reaction with silanes still shrink during ambientdrying but they do not collapse , the absence of free hydroxyl groups allow the gel to spring backits original shape 1) .

Properties of Nanogel™ AerogelsAs the name itself already says, more the 90 % of the aerogel is air which is surrounded by aporous SiO2 structure . Aerogels are nanoporous insulation materials that means the pores aresmaller than the mean-free-path of the gas molecules ( e.g. in case of air at 0° C 60 nm ) and thisnanoporosity leads to excellent thermal insulation properties .

Surface: hydrophobic ( hydrophilic )Particle size: 5 µm - 5 mmParticle shape: round or rocky

Particle density: around 120 kg /m³Bulk density: around 80 kg/m³Light transmission: translucent , opaque , opacifiedSurface area: up to 800 m²/gPorosity: > 90 %Thermal Conductivity: 15 mW/mK

This basic properties are can be modified for every application of Nanogel™ aerogels .

Applications of Nonogel™ aerogel

A )Translucent insulating light systems

The light transmission ( visual and solar ) of a 2 cm Nanogel™ layer is in the range of 70 – 80 %, the thermal conductivity around 19 mW /mK .The solar energy can pass through the aerogel into the building , and the excellent thermalinsulation of the light element minimise the thermal loss of the building.



35

The design of highly insulation glazing with U values of 0,4 W/ (m²K ) and g-values of 0,4 . x)which bring diffuse natural light in the building has been demonstrated by the ZAE 2) .Besidesglass , other transparent materials e.g. polyester , polycarbonate ,can envelope the transparent aerogel . This translucent elements bring promising newopportunities for the design of passive solar applications in construction .

Applications in construction :

Translucent wall/window elementsSky light systems / sky-domesSolar collectors for roof and wall

B) Vacuum insulation panels

Current vacuum insulation panels ( VIP’s ) are made with core material out of open cell organicfoams or inorganic material like precipitated silica’s or fumed silica’s . The microporous structureof the fumed silica cores tolerate less vacuum versus the organic foam 4) . VIP cores based onaerogels show similar flat pressure/ thermal conductivity graph . The benefit of the new fiberreinforced Nanogel™ is the reduction in panel density by 40 % , which translates to a significantpotential cost reduction for the VIP´s .In the near future we will see Nanogel™ VIP cores with a overall density of about110 kg/m³ and a correlated silica density of 55 kg/m³ 3).

Applications in construction :

Roller shutter housingsFloor insulationRoof insulationDoor fillingPipe and storage tank insulation

C) Nanogel™ Composites

In some applications does the granular aerogel not fit – solid boards or panels are required . Forforming a boards , the Nanogel™ particle need a binder , to form the aerogel granules to a solidboard . Composites out of Nanogel™ particles and organic binders bring promising performancefor new insulation solutions in construction and industrial insulation applications . Aerogelcomposites can designed with a thermal conductivity in the range of 20 –25 mW/ mK , this is areduction of 30 % versus current foam or fiber insulation materials . Besides the board applicationof Nanogel™ , this composites can be applied in a spray technology .



36

Applications in construction

Roof insulationSandwich façade boardsRehabilitation of buildings- Vapour permeable insulation elements

References

D.Smith, D .Stein,J.Anderson, W.Ackerman , J. Non Cryst.Solids 186 (1995)104A.Beck, M.Reim,W.Körner, J.Fricke, Ch.Schmidt,F-J Pötter Highly Insulating Aerogel Glazing ,Eurosun 2000 KopenhagenS.Rouanet, H.F.Eberhard , J.Floess , Novel Aerogels for Optimised Performance in VacuumInsulation Panels, ISA 64) Nanogel™ technical brochure : Original Data Nanopore ,inc.

Nanogel™ is a trademark of Cabot Corp.

High High Performance Thermal Insulations – Vaccum Insulated Products (VIP),


37

Ceramis Packaging material for VIP

Author(s): The CeramisTeam and Gérald LefebvreCompany: ALCAN Group-Lawson Mardon Neher AGAddress: Finkernstrasse 34 – CH-8280 KreuzlingenE-mail-Address: [email protected]

Fig. 1: Coater Topbeam



38

Summary• Description of the over wrapping of Vacuum Isolation Panels with a CeramisLaminate

(case Wacker Chemie GmbH with the CeramisLaminate: PET12/SiOx-PET12/PE100)

What is CERAMIS® ?• Ceramis – Description of the Electron Beam evaporation coating of Silicon Oxide.

• Advantages of CeramisLaminate for VIP.- Barriers properties against gas, moisture and other exchanges with external environment.- Mechanical stability (Gelbo-Flex stress, Folding and bending stress, Tension stress).- Thermal conductivity (non metallic/non foil structure).

Coating technologydeveloped by Lawson

Mardon Packaging

for food-,pharmaceutical- andcosmetic packaging

High barrierproperties agains t

oxygen and moisture

S uperior layeradhes ion onsubstrates

F lex-crackres is tant

PasteurizableRetortable

Excellentaroma barrier

S uitable for the microwave

Fig. 1: Ceramic thin-layer coatings

CERAMIS®- Coating TechnologyElectronbeam Evaporation with Plasma Pre-treatment

Low cost process• High web speed (10m/sec) --> high throughput

• Low cost for coating raw materials (< 1 CHF/100m2)

• Coating formulation and technology developed by our own R&D Center

High quality process• Non-reactive process (non-organic coating)

• Stable process - easy online control

• Excellent adhesion on the backing layer due to surface plasma treatment

Flexible technology

• Applicable on various substrates

• Coating without yellow tint (waterclear)

• Retortable coatings



39

CERAMIS® Film Grades• CERAMIS® PET - retortable (CT-A, CT-XA)

• retortable in a laminate structure up to 121°C (250°F), 30 min

• excellent barrier against oxygen and water vapor

• CT-XA grade without yellow tint (waterclear)

• CERAMIS® PET - (CT-D, CT-XD)

• excellent barrier against oxygen and water vapor

• CT-XD grade without yellow tint (waterclear)

• CERAMIS® oPP (CO)

• high oxygen barrier

• excellent water vapor barrier

• CERAMIS® oPA (CA)- without yellow tint- excellent barrier against oxygen and water vapor- superior mechanical strength

Barrier – PropertiesOxygen Barrier , Water Vapor Barrier , Aroma Barrier

Oxygen Permeation [cm3/(m2*d*bar]ati 25°C and 50%rH

Wat

er V

apor

Per

mea

tion

[g/(m

2 *d]

at 2

5°C

and

100

%rH

0.01

0.1

1.

10.

100.

0.01 0.1 1. 10. 100.

E VOH

PVDC

PA/oPA

PE T -metalized oPP-

metalized

CE RAMIS ®

PE T

1’000. 10’000.

S teelAluminium

Glass

CERAMIS ®

oPP

PE T

oPP PECE RAMIS ®

oPA

Fig. 2: Barrier - Permeation rates in comparison



40

Climatic Influence

0.12 0.1 0.1 0.13

0.59 0.46 0.48

2.94

0.01

0.1

1

10

100

CERAMIS® tube laminate

EVOH tube laminate

0% 25% 50% 75% 100%

relative humidity

Oxy

gen

Per

mea

tio

n[c

m³/

(m²*

d*ba

r)]

Fig. 3: Mechanical stability - Influence of humidity on oxygen barrier

Limits of use of CeramisLaminate for VIP.Target: Packaging specifications for VIP - Tests and analyses needed for this.- Limits of temperature resistance for the packaging.

(Stress tests at temperature of use in defined applications (for fridges, air conditioned systems,solar heating systems, motors, building isolation plates, ...).

- Limits of mechanical and barrier stability through time and stress tests for the packaging.- Limits of the protection of the packaging through seal areas (exchanges with external

environment through the seal of the over wrapping) for the VIP system.



41

Mechanical stability

• Gelbo-flex stress

• Folding and bending stress

• Tension stress

Fig. 5: Principle of Gelbo-Flex-testing (according to ASTM F 392-74)

Oxy

gen

Per

mea

tio

n[c

m³/

(m²*

d*ba

r)]

No. of Gelbo-Flex-cycles

0

1

2

3

4

5

6

0 10 20 30 40 50

laminate with PVDC lacquered PET (unflexed)

laminate with AlO x coated PET (unflexed)

laminate with CERAMIS®

- PET (after Gelbo Flex Test)

laminate with EVOH (unflexed)



42

Fig. 5: Mechanical stability - Oxygen permeation after Gelbo-Flex-test

0

1

2

3

4

5unflexed 5 x10 x 20 x50 x

EVOH-1

EVOH-2

Al-1Al-2

oPA met-1

oPA met-2

PET met

PET-SiOx

oPA-SiOx

coffee laminates in comparison at 25°C, 80% rH

Oxy

gen

Per

mea

tio

n[c

m³/

(m²*

d*ba

r)]

Fig. 6: Mechanical stability - Oxygen permeation after Gelbo-Flex-test

Wat

er v

apo

r p

erm

eati

on

[g

/(m

²*d)

]

0

1

2

3

4

5

unflexed 5 x 10 x 20 x 50 x

EVOH-1

EVOH-2

Al-1Al-2

oPA met-1

oPA met-2

PET met

PET-SiOx

oPA-SiOx

coffee laminates in comparison at 25°C, 100% rH



43

Fig. 7: Mechanical stability – Water vapor permeation after Gelbo-Flex-test

Alternate crosswise folding of material upwards and downwards

Fig. 8: Mechanical stability - Principle of folding test (According to NF H 00 - 030 french standard)



44

PET-film PET-metalized PET-SiOx

Fig. 9: Mechanical stability - Oxygen permeation after folding test

Oxy

gen

Per

mea

tio

n[c

m³/

(m²*

d*ba

r)]

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

unfolded folded

EVOH-1

EVOH-2

Al-1Al-2

oPA met-1

oPA met-2

PET met

PET-SiOx

oPA-SiOx

Coffee laminates in comparison at 25°C, 50% rH




45

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

unfolded

folded

EVOH-1

EVOH-2

Al-1Al-2

oPA met-1

oPA met-2

PET met

PET-SiOx

oPA-SiOx


Oxy

gen

Per

mea

tio

n[c

m³/

(m²*

d*ba

r)]


Wat

er V

apo

r P

erm

eati

on

[g/(

m²*

d)]

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

unfolded

folded

EVOH-1

EVOH-2

Al-1Al-2

oPA met-1

oPA met-2

PET met

PET-SiOx

oPA-SiOx


Fig. 12: Mechanical stability - Water vapor permeation after folding test



46

0

400

800

1200

1600

0% 1% 2% 3% 4% 5% 6% 7%

gas

per

mea

bili

ty[a

rbit

rary

un

its]

elongation

elongation limitof 7µm Al foil

PET / AlOx / PE

PET-SiOx / PE

Fig. 13: Mechanical stability - Oxygen permeation after elongation

Adhesive

Sealant-FilmPE100 µm

SiOx

PET 12 µm

Adhesive

PET 12 µmVacuum Isolation Plates

Fig. 14: CERAMIS®Laminate for VIP (CTXD based)



47

Measurements of physical properties of VIP

Dr. Hans SimmlerSwiss Federal Laboratories for Materials Testing and Research (EMPA)Building Physics / ZENUeberlandstrasse 129CH-8600 [email protected]

SummaryIn this contribution, the determination of properties of vacuum insulation boards is compared withthe existing standard test methods and product standards for conventional thermal insulationmaterials for building applications. It is shown how application related properties of VIP could betested and declared in analogy to conventional materials. Also differences and needs for additionalVIP test methods are addressed.

IntroductionIn the last years, vacuum insulation panels (VIP) have been developed and optimized to a pre-competitive stage [1]. During this time, a large amount of work has been done on definingharmonized testing and product specification standards for conventional thermal insulationmaterials by the members of the European Committee for Standarization (CEN). Although VIPs arequite different in some aspects, it is instructive to have a look at the standards for conventionalproducts. Many of the application related requirements are also important for VIP, and a few yearsfrom now, there could be one ore more harmonized VIP standard(s) along with specific testmethods needed for VIP. In CEN, mainly two technical committees (TC) are involved instandardization on thermal insulation products: In TC 88 – Thermal insulation products forbuildings – a number of general and specific test methods have been defined and established [2],and for the main product families, product standards have been developed in collaboration oftesting labs and the respective industry [3].In TC 89 – Thermal performance of buildings and building components – a number of test andcalculation methods for the determination of thermal properties of materials, façade componentsand whole buildings have been defined.

In the following sections, properties of thermal insulation boards are addressed and a comparisonbetween conventional and vacuum insulation products is made. In contrast to most of the



48

conventional products, a VIP is an assembled unit itself. As the focus is on application relatedproperties, only a short remark is made on properties of single bulk or envelope materials.

Fig. 1: Draft EN product standard prEN 13164 for extruded polystyrene (XPS) boards.

Properties of materialsFrom an application point of view, the thermal conductivity of the bulk material in function of thepore gas pressure λ(pgas) is the property most directly related to the thermal resistance of the finalproduct. For measurement, test equipment according to standards such as ISO 8302 (guarded hotplate) or ISO 8301 (heat flow meter) can be operated in a pressure controlled chamber [4]. Inaddition the thermal capacity should be known. For a detailed analysis and optimization of aproduct development process, microscopic properties, e.g. pore size distribution, IR transmission /reflection properties etc. will have to be determined by applying available methods and equipment.The envelope conserving the low pressure in the bulk material is the most important componentwith respect to the long-term behaviour of the product. Key property is the gas tightness of thematerial. For the measurement of gas permeability properties, various standard methods and testequipment are available [5]. Important is also the lateral thermal conductance which may cause asubstantial edge conductance (c.f. page 50). Various properties are related to the durability andreliability of a finished VIP, i.e. mechanical strength (e.g. tear strength), resistance to hygro-thermal, chemical or UV impact of plastics or laminates. No reference to the large number ofexisting standards is made here.



49

Properties of VIP

Thermal propertiesThe most important application related property is of course the thermal resistance or "effective"conductivity. For factory made products, the European product standards (Fig. 1) refer to specifictest methods [6] and require a manufacturer declared value λD (W m-1K-1) which shall not beexceeded by 90 % of the production at a confidence level of 90 %. Methods for the determinationof such values are described in EN ISO 10456. Furthermore, the declared value shall be valid for atime period of about 25 years, assuming a service lifetime in the order of 50 years. For some foamproducts with a high closed cell content, e.g. XPS, PUR, PIR, the thermal conductivity just afterproduction increases significantly (depending on the blowing agent) by a more or less slow gasexchange process with the environment. Therefore, the respective product standards (prEN 13164,prEN 13165, prEN 13166) contain specific ageing procedures to be applied before measuringthermal conductivity values for declaration.

Due to the strong dependence λ(pgas), changes of the cell gas content in VIP should also be takeninto account for the specification of a long-term λ-value. As an example, thermal conductivitymeasurements on a VIP with XPS bulk material sealed with laminated aluminium foil have beenperformed at EMPA (Fig. 2) before and after a heat ageing procedure adapted from the PUR draftstandard prEN 13165, i.e. 8 week storage at temperature of 60°C (PUR: 25 weeks at 70°C). It isobserved (Fig. 3) that the thermal conductivity increased from 4 to 10 mW m-1K-1. Obviously thevacuum was not broken by a failure of the envelope. Although the effect may be less pronouncedfor other bulk materials and improved getters, realistic accelerated ageing procedures, possiblywith respect to specific applications, should be determined and applied. Another question is themaximum (minimum) service temperature to prevent fast degradation or even failure of the VIP.Future VIP standards should cover the determination of those properties.

Thermal conductivity of XPS-VIPTm=10°C, before / after heat ageing

0

2

4

6

8

10

12

new 60°C, 8 weeks

λ (m

W/(

m K

))

Fig. 2: One of EMPA’s symmetric guarded hot platefacilities for low conductivity measurements onthermal insulation products (specimen size 750 x 750mm2).

Fig. 3: Thermal conductivity of a VIP before andafter application of a heat ageing procedureadapted from the draft EN product standard forPUR foams.

According to the dependence λ(pgas), pgas is the most sensitive indicator for the quality of a new oraged VIP, allowing for an immediate indirect determination of the thermal conductivity. pgas can be



50

determined approximately by placing the VIP into a vacuum chamber, reducing the pressure untilthe envelope begins to move away from the bulk material (Fig. 4). If the envelope material is thinand flexible, the interior pressure corresponds approximately to the chamber pressure. This non-destructive method is also applicable in production quality control and could be standardized.Using optical detection, the method could be run automatically and possibly with betterrepeatability than by a visual check.

Fig. 4: Approximate determination of interior gas pressure.

In addition to the one-dimensional thermal conductance, an edge conductance Ψedge due to lateralheat flow in the envelope is present in VIP:

edgeA

U

TA

Q Ψ+Λ=∆ −dim1

& (Wm-2K-1),

where area A = a x b, circumference U = 2 x (a + b) with length a and width b.

At EMPA, the edge conductance for 20 mm VIP (pyrogenic silica core) both for laminatedaluminium (about 7 µm) and for metalized Mylar envelopes has been determined by guarded hotplate measurements with one linear joint at the center (Fig. 5).

Fig. 5: Measurement of the edge conductance in a symmetric guarded hot plate facility. Two 375 x 750 mm2

specimens were placed on each side. The 1-dimensional thermal conductivity was measured with two 750 x750 mm2 specimens.

pgas

Guard area Metering area

Joint VIP

Cold plate



51

Resulting Ψedge values and calculated effective thermal conductivities for a 1 x 1 m2 board (d = 20mm) are shown in the following table (Fig. 6).

VIP envelope Ψedge W/(m K) λ1-dim W/(m K) λedge W/(m K) λeffective W/(m K)

Laminated aluminium 0.0800 0.0040 0.0064 0.0104

Metallized mylar 0.0065 0.0040 0.0005 0.0045

Fig. 6: Measured edge conductance and effective thermal conductivity of a VIP (1 x 1 m2, d = 20 mm).

In the case of the relatively massive Al envelope, the edge conductivity is larger than the corecontribution. For the metalized high barrier Mylar foil, the effect is in the order of 10 %. Becausethe geometry factor is

( )112 −− += baA

U,

both linear dimensions must be "large" in order to reduce the edge effect. An example is shown inFig. 7: Although the area in the second case (2.0 x 0.6 m2) is larger, the effective conductivity ishigher than with the 1 x 1 m2 panel.

Effective thermal conductivityincluding edge conduction

0

2

4

6

8

10

12

laminated Alu1 x 1 m2

laminated Alu2 x 0.6 m2

metallized Mylar1 x 1 m2

metallized Mylar2 x 0.6 m2

Panel type

λ ((

mW

/(m

K))

edge1-dim

Fig. 7: Comparison of effective thermal conductivities for different panel envelopes and areas.

It is evident that the edge conductance Ψedge should be determined and declared by themanufacturer similar to the long-term one-dimensional conductivity.

Geometric and mechanical propertiesEN standards exist for the determination of "simple" geometric properties like length, width,thickness, squareness and flatness of thermal insulation products (EN 822-EN 825). In the ENproduct standards, tolerances and declaration rules are stated. These quantities are important forpractical reasons of application or further manufacturing, also for VIP. Because of the additional



52

sealing stripe of the envelope, those quantities have to be redefined and declared in a commonway.There is also a number of EN test methods for mechanical (force) properties: compressive andtensile stress behaviour (EN 826, EN 1607), bending strength (EN 12089), behaviour under pointload (EN 12430), thickness in floating floor applications (EN 12431), compressive creep behaviour(EN 1606). Depending on the application, some of these properties may be of interest for VIP too.However, the applicability of the methods has to be checked carefully.

Durability / ReliabilityVarious EN standards are available for testing of the dimensional stability under standardconditions 23°C / 50 % r.H. (EN 1603), specified temperature and humidity conditions (EN 1604),and specified compression and temperature loads (EN 1605). Also for VIP, some of these methodsmay be important for specific applications. However, the issue for VIP is not just the degradation ofcertain properties over a long time period (durability).Other than with conventional insulation products, a dramatic change in the thermal insulationoccurs with VIP in case of a failure of the seal or if the vacuum is damaged by another mechanism.Furthermore, the failure will affect at least the area of a whole panel or larger areas in case of asystematic process. Therefore, reliability and durability testing is very important for the acceptanceand successful application of VIP. The (expected) long service lifetime and typical loads in buildingapplications have to be taken into account:

• Temperature and humidity variation (most applications)

• Mechanical impact

• Chemical impact (e.g. in contact with concrete, outdoor air)Suitable procedures have to be discussed and tested.

Acoustic propertiesAs for conventional thermal insulation boards, the dynamic stiffness (EN 29052-1) will be neededfor floating floor applications. In special cases, the sound absorption coefficient (EN 20354) may beof interest.

Properties of VIP construction elementsFor assembled construction elements with built-in VIP basically the same standards and toolsapply as for conventional elements. They are not listed here in detail. The main focus will be on themeasurement and calculation of the U-value of assembled construction elements. Attention shouldbe drawn on thermal bridge and joining details which are more critical in elements containing VIP.In addition to hot box measurements, IR imaging is a suitable method for the detection of thermalweak points (Fig. 8). Accordingly, specific moisture transport and/or condensation questions shouldbe investigated carefully. For many applications, the sound insulation behaviour of a wall or ceilingconstruction will be needed too.It is of course not possible to detect and to solve all application related problems "in advance".Some more years of experience will be needed to identify promising application and major problemareas. In particular a detailed knowledge transfer to the building industry and to the public will benecessary if VIPs should become generally available for construction companies or even in thehobby market in future.



53

Fig. 8: Calibrated hot box and IR image of a wall element (EMPA).

References [1] e.g. R. Caps, R. Neusinger, J. Fricke, Vakuumdämmung und Schaltbare Wärmedämmung

für die Fassade: Erste Erfahrungsberichte, Proceedings 10. Bauklimatisches Symposium,Dresden, 27.–29.09.99.

[2] General test methods for factory made thermal insulation products: EN 822 – EN 826, EN1602 – EN 1609, EN 12085 – EN 12091, EN 12429 – EN 12431.

[3] Thermal insulation product standards: prEN 13162 - prEN 13171. [4] Instituts: e.g. ZAE Bayern, D-97074 Wuerzburg (Gemany); NPL, UK-Teddington Middx.,

TW11 0LW (Great Britain). [5] Instituts: e.g. ZAE Bayern, D-97074 Wuerzburg (Gemany); EMPA, CH-9014 St. Gallen

(Switzerland). [6] prEN 12667: Thermal insulation - Determination of thermal resistance by means of guarded

hotplate and heat flow meter methods – Products of high and medium thermal resistance.



54



55

VIP’s for advanced retrofit solutions for buildings

Dr. Ralf MaternaZZ WancorAlthardstrasse 5CH-8105 [email protected]

SummaryDuring the last few years, building owners and architects have been demanding more efficientinsulation materials. The reasons are the rising requirements for the thermal insulation of buildings,and the resulting increase in the thickness of the materials. The necessity for efficient, as well asroom-saving insulation materials is felt especially in renovation projects with limited availablespace. With renovations in particular, the space is often either too expensive or simply notavailable to meet the current thermal insulation standards. Thanks to the vacuum insulation panels(VIP), an insulation product is now available with which the desired thermal insulation can beachieved with thin panels.The first promising experiences are being made with VIP in various applications, mainly inrenovation projects. The results have convinced us that, over time, such high-performanceinsulation materials will prevail in building construction.

Range of application for vacuum insulation panels in buildingsIt is necessary to differentiate between applications on construction sites and in workshops. Inworkshop conditions, the panels can usually be fitted unprotected into prefabricated elements suchas walls, doors, roller blind boxes, and window framing. For many applications on site, it isimperative to equip the panels with a mechanical protection.

Application on the building site

Rough construction site conditions, exterior applicationsIdeally, under well controlled conditions, unprotected vacuum panels can be applied on site with anacceptable injury risk. For applications in typical site conditions, such as external thermalinsulation, pitched or flat roofs, the risk of damage is great. For these applications, it is stronglyadvised to equip the panels with an adequate mechanical protection.A cover of the vacuum insulation panels made of EPS, XPS or mineral wool has proven suitable.These insulation elements, developed by ZZ Wancor, can have dimensions of 600 x 1000 mm with



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a thickness of 40 mm, for example, and can beapplied like conventional insulation panels.Besides the full-size panels, half- and quarter-size panels are available as well as custom-sized ones. Obviously, the panels cannot be cutto size, therefore the borders and joints must beadjusted with conventional insulation material.Such insulation elements have been installed asinternal thermal insulation, in flat roofs and roofterraces, as well as for the framing of windowsand exterior doors.

Fig. 1: Mechanical protection through coverage withEPS, XPS or mineral wool

The following advantages of covered insulation panels thus became apparent:

• The panels can be handled as usual, except that they should never be perforated or cut.

• The accuracy of the dimensions is much higher than that of uncovered panels.

• The problem with the panel junctions has been solved by pushing them close together andseveral mm can even be removed to adjust the panels.

• With a cover of approx. 10 mm and a minimum of precaution during transportation andhandling, the panels are sufficiently protected for most applications.

Dry building site, interior applicationIf the necessary precautions are taken, the interior building environment can be sufficientlycontrolled for the use of unprotected vacuum insulation panels. In such a typical dry siteenvironment, the workmen are used to deal with delicate construction materials and elements.To date, the unprotected vacuum insulation panels have been used for the internal thermalinsulation of walls and floors.

Fitting into prefabricated building elements under defined workshop conditionsIn the well-controlled conditions of a workshop or a factory, the unprotected vacuum insulationpanels can be fitted into prefabricated building elements without problems. Border losses areminimized by the high accuracy of the prefabrication, allowing a perfect fit without gaps.Furthermore, the cost of customized panels can be reduced if they are produced in sufficientlylarge numbers.To date, ZZ Wancor has fitted unprotected vacuum insulation panels into roller blind boxes,exterior doors and special wall elements used in wood construction.



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Experiences made in demonstration projects

Flat roof insulationIn renovations of flat roofs in particular, there is often a limited space available for insulationmaterial, or considerable adjustments have to be made at the joints and seals. Thanks to thevacuum insulation panels, it is now possible to improve the thermal insulation without altering theoriginal thickness of the roof construction.

Thermal insulation of a terrace in Leimbach/TGThe rooftop terrace of a house in Leimbach/TG is a typical application example. The roof coveringhad become impermeable over time and needed to be replaced along with the soaked corkinsulation. Due to the construction, it was impossible to increase the original insulation thickness of4 cm without having to replace the windows and doors along the entire width of the terrace.The vacuum insulation panels covered with extruded polystyrene from ZZ Wancor were used. Full-half- and quarter-sized panels were installed like conventional insulation panels. Edges and jointswere fitted with panels of extruded polystyrene, covering approximately 10 % of the roof surface.Using a panel only 40 mm thick, a mean U-value of 0.29 W/m²K was achieved over the entire roof,corresponding to a polyurethan panel with a thickness of 90 mm!

Fig. 2: Cross-section of the terrace construction. The edges were made with extruded polystyrene.

Passive houses in Wolfurt, VorarlbergThe problems encountered in this project were slightly different. The standard for passive housesrequires U-values between 0.10 and 0.15 W/m²K which requires insulation thickness of up to 40cm (!). With such requirements, it is practically impossible to insulate roof terraces efficiently.Instead of using 40 cm thick panels of polystyrene, the thermal insulation of the terraces(measuring approximately 30 m²) was carried out with 5 cm thick vacuum insulation panels,

Roof construction:

Paving slabsGravel, sandWaterproofing membraneCovered vacuum insulation panelVapour barrierConcrete



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achieving the same insulation factor! The edge effect was insignificant since the panels werecustom-made and measured 242 x 80 cm, a surface of almost 2 m².This application revealed how difficult it is to work with unprotected panels on site. Lack ofprecaution during transportation to the site and during assembly resulted in several damagedpanels that needed to be replaced.

Abb. 3a: Passive house in Wolfurt, Vorarlberg(Architect Gerhard Zweier, Wolfurt)

Abb. 3b: Completion of the terrace using 5 cm thick vacuum insulation panels

Insulation of pitched roofsThe insulation on top of pitched roofs’ rafters is one more interesting application of coveredvacuum insulation panels. Due to design imperatives (visible rafters, increased room height) orbecause the attic is inhabited, it is often impossible to fit insulation panels between or under therafters. Moreover, it makes sense to improve the thermal insulation of a roof whenever its tilesneed to be replaced. The sole disadvantage of this otherwise superior rafter insulation is theresulting increase in ridge height. Limitations due to construction laws as well as the heighteningof the roof requiring adjustments on the eaves and borders of the roof, as well as on the roofwindows, can result in increased costs and impair the architecture.The vacuum insulation panels offer a solution for simple roofs that only need a slight elevation, ornone at all. The following example illustrates a renovation proposal for a one-family house nearZürich. Due to the proximity of the airport, vacuum insulation panels covered with mineral woolwere selected for noise control.The insulation panels from ZZ Wancor are fixed seamlessly on top of the vapor-barrier coveredtimber boards, using a special vapor permeable underlay which is fixed by means ofcounterbattens. The principle of this construction corresponds to a conventional warm pitched roofconstruction. The specific weight and the 3 cm width of the mineral wool along the length of theinsulation panels has been calculated so that the counterbattens can be fixed through the seamswithout risks.



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Fig. 4: Construction of mineral-wool covered vacuum insulation panels on a pitched-roof insulation.

Window framingIn older buildings, thewindows are often too smallmeasured to today'sstandards. If the windowframing is going to besufficiently insulated during athermal renovation, theavailable daylight will beunbearably reduced.Enlarging wall openings isusually too costly and oftenimpossible due to thetechnical characteristics of thebuilding. The insertion of VIParound the windows canconsiderably improve thesituation without decreasingthe inner lighting.

Fig. 5: Cross section and groundplan of a feasible façaderenovation. Installing VIP panelsaround the windows provides anideal solution to the thermal jointsproblem without considerabledeterioration of the interiordaylight situation.

Cross section

Ground plan



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Internal thermal insulationFor renovations, internal thermal insulation is always considered where external insulation is notfeasible due to special marginal conditions (with listed buildings for example), or when the expensewould be prohibitive, for instance when the façade is still intact.However, lack of space or connection problems often limit the possible thickness of the internalinsulation. In this case as well, vacuum insulation permits an optimal thermal insulation withminimal space loss.

Two variants have been tested in a one-family housefrom the 30’s in Zürich:

Implementation using EPS-lined vacuum insulationpanelsIn this variant, the covered ZZ Wancor insulationpanels were glued onto the 30 cm thick brick wall andcovered with plaster, as with conventional EPS-panels.The edges and socket-joints were completed withconventional EPS material.The owners have to receive appropriate directionsconcerning this type of wall insulation to ensure that nonails etc. are thoughtlessly driven into them.

Fig. 6a: Sectional drawing of an internal thermal insulationusing 4 cm thick EPS-covered VIP panels. This way, a meanU-value of 0.26 W/m²K can still be achieved over the entirewall, with a total thickness (including 5 mm plaster) of only45 mm.

Implementation with glued panels and a free-standingwall consisting of 4 cm thick gypsum boardsIn this variant, the vacuum panels were glued directlyonto the wall using a polyurethane glue. The jointswere then covered with an aluminum-laminatedadhesive tape. Since unprotected insulation panelswere used, appropriate care had to be taken withhandling on the site. Compared to the first variant, weachieve a better U-value with this construction free ofthermal bridges, and we also have the decisiveadvantage of obtaining a wall that can be used withoutrestrictions.

Fig. 6b: Section through an internal insulation using 2 cmvacuum panels and a 4 cm gypsum wall. A mean U-value of0.24 W/m²K is achieved with a total thickness of approx. 6.5cm, including the 4 cm of the gypsum wall.



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Floor insulationA project for the Blood Donor Center Bern AG consisted in a major alteration of a building,including the installation of a deep-freeze room of 50 m² needed to preserve the blood. The onlyspace at our disposal for the floor insulation was the approx. 10 cm of the removed screed.However, the energy laws of Bern require an insulation corresponding to at least 25 cm ofpolyurethane.

Fig. 7: Section through thefloor of the deep-freeze room.The 2 layers of vacuumpanels of 25 mm each,correspond to the insulationachieved with an approx. 25cm thick polyurethaneinsulation..

Structure of the floor- Plaster- Polyethylene-foil- Protection mat of 6 mm- 2nd layer of vacuum insulation panels of 25 mm- 1st layer of vacuum insulation panels of 25 mm- Protection mat of 6 mm- Vapor barrier- Concrete

The problem with the lack of available space was again solved by using the highly insulatingvacuum insulation panels. Two layers of vacuum panels were used to improve the safety. Thecustomized panels were staggered to avoid potential thermal bridges over the joints as much aspossible. Temperature sensors were installed underneath the insulation panels to ensure apermanent control of their function.

Roller-blind boxesDue to lack of space, the lintels of roller-blind boxesoften prove to be problematic for thermal insulation.A thin thermal insulation provides a satisfactorysolution, as seen in the roller-blind boxes used in aone-family house in Meilen.

Fig. 8: Installation of vacuum insulation panels in rollerblind boxes



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Exterior doorsThe installation of vacuum insulation panels in exterior doors was carried out as well. This way, theU-value of a door with a standard thickness can be at least halved, thus eliminating one of the lastweak points in the thermal insulation of a building.



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Existing and future applications for advanced low energy buildings,especially passive houses

Dr. Wolfgang FeistPassive House InstituteRheinstr. 44/46D-64283 Darmstadt, Germanywww.passiv.de

Summary: Advanced low energy houses ... quo vadis?

Unfortunately, extra investment in energy-saving technologies rises in step with decliningconsumption; this is a fact known by economists as the 'law of diminishing marginal utility'. It isreadily illustrated by the costs of increasingly thicker thermal insulation: The last centimetre of, forinstance, a 20 cm insulation costs the same as the first centimetre (namely about 0.50 Euros perm²), but only saves a tenth of a litre of heating oil per square metre per year – not much comparedto the 10 litres saved by the first centimetre. Consequently, increasing insulation thickness haslong been criticized as economically unacceptable. Were the critics right? In very basic terms yes,but the limits are by no means reached as quickly as many have claimed. The tenth centimetre stillprovides cost-effective heating oil savings, even if oil only costs 11 Eurocents per litre. Thefifteenth centimetre still saves oil at investment costs below 22 Eurocents per litre. However, it isclear that the fiftieth centimetre would only become cost-effective at an oil price of about 2 Eurosper litre. Such high oil prices will scarcely be reached in the future. The law of diminishing marginalutility applies similarly to improved window glazing and improved heat exchangers for heatrecovery (with larger surface).The better the energy performance of a building, the higher the requisite extra investment – or atleast that is how it would seem at first sight! If we remain within the realm of conventionaltechnology, optimum efficiency technology is reached in the range of a low-energy house, at about70 kWh/(m²a). A typical single-family house with a floor space of around 150 m² then stillconsumes about 1000 litres of heating oil per year for space heating, costing its occupants about320 Euros. If the next step to the 3-litre house (30 kWh/(m²a)) is taken, this saves just 180 Eurosper year. That is the sum that an economically thinking house-buyer would spend annually oninterest and repayment of the debt incurred for the energy-saving investment required to upgradethe building to a 3-litre house, rather than for heating oil. At an interest rate in real terms of 4% perannum, this gives scope for investment of about 3400 Euros; that is how much more the 3-litrehouse could cost than a normal low-energy house. Using the same calculation, only a further 1700Euros would be available to upgrade the 3-litre house to a 1-litre house.However, there is a way out of the trap of diminishing marginal utility: to build both energy-efficiently and at low extra investment cost. The decisive point is this: The scope must be exploitedto save investment costs through improved efficiency technology. For this, the thermal insulation ofthe building must be so good that it permits decisive simplification of conventional building servicesystems, and thus lower investment costs. Precisely this is the passive house approach: Passivehouses are buildings with such good thermal insulation that heating systems are simplifiedradically.



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The passive house is the 1-litre house – and is affordableIn the passive house, technology and economics are considered in unison from the very outset. Toachieve further improvement above and beyond the low-energy house, it is essential to recoverheat from the extract air. If no heat recovery system is in place, annual ventilation heat lossesamount to about 35 kWh/(m²a) – sufficient fresh air supply is essential for health reasons and tomaintain acceptable levels of comfort in the house. These ventilation heat losses can only bereduced by means of heat recovery – and residential ventilation systems with heat recovery areexpensive, costing about 5000 Euros in a new-build house. This investment comes on top of thenormal cost of building services. Very good heat recovery systems can yield net annual savings ofabout 50 Euros in operating costs if the electricity consumption for fans and the costs for filters aretaken into consideration. This alone cannot justify the high investment costs. But what if theventilation system provides space heating at the same time? The system has to convey freshsupply air to each room in any case; this air can also transport heat. If a building has such goodthermal performance that this supply air suffices by itself to ensure comfort, then a further heatdistribution system is rendered superfluous. This is the basic principle of the passive house:Excellent thermal insulation plus high-quality ventilation render superfluous the double investmentin building services (this is illustrated by the Table).

Standard low-energy house70 kWh/m²

Ultra-low-energy house30 kWh/m²

Passive house10 kWh/m²

Ventilation without heat recovery Ventilation with heat recovery Ventilation with heat recovery

Conventional heating system isrequisite

Conventional heating system is stillrequisite

Supplementary supply air heatingsuffices

"Simple" building services investment:

Heating system ≈10,000 Euros

"Double" building servicesinvestment:

Heating system ≈10,000 Euros

Ventilation ≈ 5,000 Euros

Back again to "simple" buildingservices investment:

Ventilation with supplementary heatingregister suffices by itself

≈10,000 Euros

Precondition: thermal insulationperformance compliant with GermanBuilding Energy ConservationOrdinance (Energie-Einspar-Verordnung)

Precondition: thermal insulationperformance better than GermanBuilding Energy ConservationOrdinance

Additional cost for this:1,000 to 3,000 Euros

Precondition: thermal insulationperformance far better than GermanBuilding Energy ConservationOrdinance, reaching 15 kWh/(m²a)

Additional cost for this:≈6,000 Euros

The heating, ventilation and air-conditioning (HVAC) industry need not fear this development. Totalinvestment in building services remains roughly the same. What the passive house means forbuilding services is, simply, that, at roughly the same level of value added, conventional heatingsystems are replaced by innovative ventilation systems. In economic terms this at first makes nodifference. However, in actual fact the outcome is much better, for throughout building use it yieldssavings, because the operating costs corresponding to the net energy savings provided by heatrecovery are saved. Moreover, there is the important additional benefit of the gain in comfortprovided by the ventilation system. This, however, is only possible if the thermal insulation of thebuilding envelope is improved substantially. This again costs money, but not more than thecapitalized energy cost savings that the improved insulation yields. The total extra investmentrequired for a passive house compared to a standard low-energy house is made up of the extracost of the improved thermal envelope (approx. 6,000 Euros incl. windows) plus the cost of theventilation system, which can be recouped by the simplified building services. In sum, this totalextra investment will not be higher than for a 3-litre house, but the energy savings realized arehigher – the passive house can therefore be economically superior.



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Passive house principles: High-performance innovations – Thermal insulationThe thermal insulation of the building envelope of a passive house needs to be improved quitesubstantially compared to conventional designs. This has two reasons:

• In order to achieve the requisite low heating loads of less than 10 W/m², envelope heat lossesneed to be minimized (heating load requirement)

• Temperature differences between the indoor surfaces of exterior building elements and theindoor air must be kept small: otherwise radiative temperature asymmetries and undesiredindoor air circulation would result, which would impair occupant comfort (comfortrequirement)

It has emerged that the second requirement is easier to meet than the first. With normal ceilingheights, draughtlessness and sufficient operative temperatures are achieved in Central Europeanclimates if the thermal transmittance (U-value) of the exterior building elements is equal to or lessthan 0.8 W/(m²K). The indoor surface temperature is then about 17°C (at an exterior designtemperature of -10°C, and indoor air temperature of 20°C). The U≤0.8 W/(m²K) requirement isalready more than fulfilled today for wall, roof or ceiling constructions in new buildings complyingwith the 1995 German Thermal Insulation Ordinance (Wärmeschutzverordnung 1995). Under thatOrdinance, U-values are already between 0.17 and 0.5 W/(m²K). By contrast, the Uw≤0.8 W/(m²K)requirement can only be achieved for windows by means of high-performance glazing andsuperinsulated frames.The demands placed upon the insulation performance of the opaque building elements are thusdetermined by the first – the heating load – requirement. In what manner the reduction of heatlosses is achieved is irrelevant to the function of the passive house. There are various options:– Reducing exterior surface area by means of compact design:

This is doubtlessly the most cost-effective approach.– Improving the utilization of radiation incident on the exterior surface (by means of translucent

insulation, semi-translucent insulation, solar facades).– Enhancing insulation effect by means of thicker insulation layers or reduced thermal

conductivity of materials.The second of these options can also be calculated by applying an equivalent U-value. If Uopaque isthe mean U-value of opaque elements of the building envelope and Aopaque is the total surface areaof these elements, then Aopaque ·Uopaque characterizes the transmission heat loss of all opaquebuilding elements. If we assume, in order to derive simple reference values, that the window U-values of a passive house must be around 0.8 W/(m²K) (they must at all events not be higher;substantially better values are not yet available today), and further consider the functionaltransmission heat requirement (≤10 W/m²), then, in a first approximation, we find that theequivalent U-values of

opaque passive house envelope elementsmust range between 0.1 and 0.15 W/(m²K).

Compared to the values common today, these are exceedingly low U-values. Nonetheless, a broadrange of building envelope elements meeting passive house standards is now available on themarket [Feist 2001]. The list of products that come into question is growing constantly, e.g.:

• ’Classic’ external thermal insulation compound systems ("ethics"):A thermal insulation system with 300 mm insulation (thermal conductivity: 0.04 W/mK) withexterior plaster coat, interior masonry and gypsum plaster, gives U≈0.13 W/(m²K) with a totalthickness of approx. 500 mm.

• 'Classic' light timber construction:



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A timber panel element with 280 mm T-beams, rock wool filling (thermal conductivity: 0.035W/mK), interior and exterior panelling and weather-boarding gives U = 0.12 W/(m²K) with atotal thickness of 390 mm.

• Vacuum insulation:A vacuum powder panel with a thermal conductivity (λ) of 0.006 W/(mK) and 40 mm thicknessalready achieves on its own a U-value of less than 0.15 W/(m²K). Together with a thin (e.g.metal) load-bearing structure, a U-value in the region of 0.11 W/(m²K) can be achieved with atotal building element thickness of less than 200 mm. This will make extremely thin exteriorpassive house elements possible in the future. High-vacuum thermal insulation elements withmineral fibre spacers and stainless steel panelling have even lower thermal conductivity andare already available on the market.

• Translucent plaster:In these systems, a roughly 150 mm thick semi-transparent insulation layer is protected on theoutside with a translucent plaster. Absorption of short-wave global radiation is thus shiftedinwards, into the outer region of the insulation layer. The inner, 'dark' region of the insulationlayer is requisite above all for summertime thermal insulation. Depending upon the load-bearing structure used, this system has a total thickness of 28 to 35 cm, and an equivalent U-value well below 0.1 W/(m²K).

Two quality parameters are decisive for the efficacy of thermal insulation, and particularly so inpassive houses:– the elimination of thermal bridging, and– air-tightness.Both have been discussed at length elsewhere [AkkP 16; Peper 1999]. Built passive housesprovide an excellent reference basis, showing that thermal-bridge-free design and extremely lowair leakage values below 0.6 h-1 are achievable today, with all constructions and all architecturaldesigns.A note on costs: As shown in [Feist 1997], at current energy prices (0.03 Euro/kWh), the insulationperformance of exterior building elements with optimum total cost is between 0.2 and 0.35 W/(m²K)if only the operating cost savings are apportioned to paying back the insulation. Passive houseinsulations, with U ≤ 0.15 W/(m²K), are definitely 'thicker' than this micro-economic optimum. For aconventional structure, the insulation material thickness corresponding to Uoptimal=0.2 W/(m²K) isabout 180 mm – which is a good low-energy house standard. Conventional passive houseinsulations are, at 300 mm thickness, more expensive than an optimum-cost insulation by about 5to 7.5 Euros per m² building element surface in terms of investment cost. The net present value ofthe additional energy cost savings figures 2.5 Euros per m², meaning that extra costs of 2.5 to5 Euros per m² remain. The extra investment for the passive house insulation standard amounts toabout 2,500 Euros for a single-family house if a careful eye is kept on costs. There is a goodprospect of recouping this through lower maintenance costs.



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Passive house windows: High comfort includedIn the passive house, windows have a key function. The passive house standard can only beattained with window qualities far beyond the conventional. It has been set out above for opaquebuilding elements that in order to provide sufficient occupant comfort without indoor radiators belowthe element, it is necessary in Central Europe to achieve U-values equal to or lower than0.8 W/(m²K) (at design temperatures around -10°C). While this requirement can be met for opaqueelements without particular difficulty, windows with such a low heat loss are better by about a factorof 2 than the windows with low-emissivity double glazing and wood or plastic frames commonlyused today (2001). To achieve the indispensable quality improvement by a factor of 2, it neithersuffices to only improve the glazing (triple low-emissivity glazing has U-values between 0.6 and0.8 W/(m²K)), nor to only use better insulated frames (with U-values between 0.5 and0.9 W/(m²K)). It is rather essential to combine both, while at the same time reducing substantiallythe thermal bridging of the spacer at the edge of the glazing. Only the combination of:

• low-emissivity triple glazing +

• insulated frames +

• reduced glazing spacer lossesprovides a window suitable for passive houses [AkkP 14].The greatly improved windows for passive houses currently still have their price; the client mustexpect extra costs per square metre window area of about 100 Euros. For a typical single-familyhouse, the extra investment for windows complying to passive house standards thus amounts to3,000 to 3,500 Euros.

Passive house experience in built projectsBy the end of 2000, some 800 housing units in passive houses were occupied in Germany.The technological fundamentals for the passive house are the same as for the low-energy house:good insulation, better windows, comfortable ventilation. Quality improvements in these threespheres have proven themselves and the confidence of users that further improvements will havesimilarly positive effects has risen.It was striking in the architectural design competitions held in the course of the past year thatissues relating to 'workmanship', such as a well-insulated envelope, thermal-bridge-free design,and airtight design became ever more matter-of-course elements of the designs submitted.Passive house architecture is gradually finding ways to bring the inherent benefits of the concept tothe fore. The reduced effort required for building service systems and the inherently goodventilation increase the degree of freedom for the architects.The responses of occupants are exceedingly positive: "We never froze", "If we were to build ahouse again, it would certainly be a passive house", "We practically never heated" are typicalcomments.Painstaking energy consumption measurements were carried out in a whole series of buildings.The measurements undertaken in the passive house estates are particularly illuminating. The firstpassive house estate, with 22 terraced houses, was completed in the Dotzheim district ofWiesbaden, Germany, in August 1997 by the developer Rasch & Partner, and has been occupiedsince then. Here two institutes – Institut Wohnen und Umwelt and the Passive House Institute –carried out detailed measurements. In the 1998/99 measurement year, a measured specific heatconsumption (district heat) averaging 13.4 kWh/(m²a) (average across all 22 houses) was found.By chance, this corresponds fairly exactly to the value calculated using our 'Passive HousePlanning Package' for this estate, namely 13.5 kWh/(m²a). The measurement results in Wiesbaden



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have now established for a statistically sufficiently large population of users in terraced houses thatthe passive house standard does indeed deliver in practice the energy savings previouslycalculated. The data documented here show there has been no significant ventilation by openingwindows in the cold season in the 22 passive houses – if there had been, then consumption levelswould have been much higher than measured.Measurement results are now also available for the passive house estate in the Kronsberg districtof Hannover, Germany (Fig. 1). In these houses, too, the target was already achieved in the firstyear, with a measured specific heat consumption of less than 15 kWh/(m²a). The Hannover-Kronsberg passive house estate is one of the German sub-projects within the context of theCEPHEUS (Cost Efficient Passive Houses as European Standards) programme supported by theEuropean Union.

Figure 1: Specific heat demand measurements of the 32 houses in the Hannover-Kronsberg passive houseestate (developer: Rasch&Partner): Consumption is lower than in conventional buildings by a factor of 10.

We are awaiting with great interest the results of measurements at the two government-assistedmulti-family passive houses in the city of Kassel, Germany (Fig. 2). Here GWG Kassel(Gemeinnützige Wohnungsbau Gesellschaft, a non-profit housing association) has built two largeapartment buildings with a total of 40 units to passive house standards. Renowned architects haveteamed together to plan these masonry structures, which are also a part of the CEPHEUS project.Here, for the first time, a high-efficiency ventilation system has been used in a multi-storeyapartment building in which central heat exchangers are installed on the roofs, but fans aredecentralized in the units [Otte 1999].

0

20

40

60

80

100

120

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

spec

. hea

t con

sum

ptio

n [k

Wh/

m²]

Calculated mean 12.2 kWh/m²

Hannover passive houses: Measured mean 14.9 kWh/m²

Savings 80 %

German Building Energy Conservation Ordinance (EnEV) standard 73.3 kWh/m²

Mean 1995 German Thermal Insulation Ordinance (WSVO) standard 107.5 kWh/m²

Hanover passive house estate: 32 terraced houses within CEPHEUS

project; Architecture: Rasch&Grenz



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Figure 2: A CEPHEUS project in Kassel, Germany: Two multi-storey apartment buildings totalling 40 unitswere built here by GWG Kassel on the site of a former military barracks. Three teams of architects (Prof.Schneider; HHS; ASP) designed the buildings. Vacuum insulation panels are used in some casement doorsas opaque filler panels.

Measurement results from two operating years are now also available for the first administrativebuilding built to passive house standards, by the Wagner&Co. company in Cölbe near Marburg,Germany. Measurements are being supported by the Germany Ministry of Economics (within thecontext of the SolarBau programme, coordinated by BEO/Jülich) and carried out by the Universityof Marburg. The heat extracted from a microcogeneration system with 12 kW thermal outputsuffices to heat the 2180 m² floor space of the building. As is characteristic of a passive house,heat is supplied exclusively via the supply air of the high-comfort ventilation system. Summertimecomfort in the offices is also convincing: Despite very hot periods, temperatures in the house havebeen found to generally remain below 26°C. The passive-house office building has no air-conditioning system; the comfortable indoor climate is achieved by means of night-time ventilation(automatically opening skylights), temporary shading and supply air cooling in a subsoil heatexchanger [Wagner 1999].

The number of projects that have now been realized or are under construction has become solarge that not all can be described in detail here. Up-to-date project presentations are available atthe Passive House Institute's website (www.passivehouse.com).



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References:

[AkkP 14] Arbeitskreis kostengünstige Passivhäuser: Passivhaus-Fenster; Protokollband Nr. 14,Passivhaus Institut, Darmstadt, December 1998

[AkkP 16] Arbeitskreis kostengünstige Passivhäuser: Wärmebrückenfreies Konstruieren;Protokollband Nr. 16, Passivhaus Institut, Darmstadt, June 1999

[Feist 1997] W. Feist: Überprüfung der bedingten energetischen Anforderungen imGebäudebestand ; Studie im Auftrag des BmBau, Passivhaus Institut, Darmstadt, Dec.1997

[Feist 2001] W. Feist: Gestaltungsgrundlagen Passivhäuser ;Verlag das Beispiel, Darmstadt, 1stedition, 2001

[Otte 1999] Joachim Otte, Ing.-Büro innovaTec: Besonderheiten bei der Ausführungsplanungeiner Lüftungsanlage im Geschoßwohnungsbau; in Arbeitskreis kostengünstigePassivhäuser: Dimensionierung von Lüftungsanlagen in Passivhäusern;Protokollband Nr. 17, Passivhaus Institut, Darmstadt, June 1999

[Peper 1999] Søren Peper, Wolfgang Feist: Luftdichte Projektierung von Passivhäusern ;CEPHEUS-Projektinformation Nr. 7, Passivhaus Institut, Darmstadt 1999

[Wagner 1999] R. Wagner; A. Spieler; K. Vajen; S. Beisel: Passive Solar Office Building: Results ofthe first Heating Period; in ISES Solar World Congress, Jerusalem, 1999



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VIP’s for buildings - Research and Development

IEA / ECBCS Annex 39

Markus ErbDr.Eicher+Pauli AGKasernenstrasse 21, 4410 [email protected]

SummaryIn the area of building insulation the need for better materials and systems has grown. There arealready some products available, e.g. Vacuum Insulation Panels (VIP), which are suitable as abasis for the development of building components with much lower U-Values than what is usedtoday.The R&D programme ‘High Performance Thermal Insulation Systems in Buildings’ will answerquestions in the area of basic materials, especially VIP, and will support companies to developHiPTI systems for the building envelope and HVAC components. This support consists in bringingtogether all relevant expertise from research, development and planning.The project will be carried out under the IEA Implementing Agreement ‘Energy in Buildings andCommunity Systems’ as Annex 39. Its activities are subdivided in three Subtasks: A) Basicconcepts and materials, B) Application and systems development and C) Demonstration /Information dissemination.

Insulation and buildings• Legal insulation standards for new buildings are getting stricter

• Low Energy Building Concepts, with even lower U-Values, are getting more and more popular

• Space in retrofit applications or in HVAC-installations is limited

➩ To fulfil the new requirements, conventional insulation materials often need too much space,which is- expensive (new buildings) and/or- not available (retrofit and HVAC-installations)



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In terms of thermal conductivity, windows, particularly glazings, experienced substantialimprovements during the last years.Now it’s time to start a similar efficiency development for other building components. Which isexactly the objective of the R&D-programme described below. Its title is:

‘High Performance Thermal Insulation Systems in buildings’: HiPTI.

DefinitionsIn the programme we want to work not just on insulation materials, but insulated components forbuildings, which we call systems (façade element, door, window frame, etc.). The HiPTI systemswe want to develop, should have an overall thermal conductivity of ≤ 15 mW/(mK) in the insulationlayer. This means that thermal bridges, which in HiPTI’s will get more important, have to beconsidered carefully. Furthermore, the value mentioned above has to be understood as anaverage during the life-span of a system.This definition ensures, that the HiPTI systems as a hole will perform, in terms of heat conductivity,at least twice as good as the best products available today and therefore are definitely interestingfor planners (architects, engineers).Moreover, we want to focus on systems, in which today conventional (opaque) insulations (fibresand foams) are used. Optical properties as translucency or transparency, e.g. ‘window technology’,are not subject of the programme.

As a consequence of this definition, Vacuum Insulation Panels (VIP) will play a major part in theprogramme, since no other insulation reaches the required thermal conductivity limit.

General objectives of the R&D-programmeThe today situation fulfils the basic requirements to develop and commercialise HiPTI systems. Butthere are two main areas, where work has to be done, to get the process started as shown inFigure 1.



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D:\E+P\IEA\Referate\[Ref_WS01.xls]R_D Curve

Research - System Development - Market

0.0

0.2

0.4

0.6

0.8

1.0

0 5 10 15

Time [year]

Act

ivity

[%]

Sta

rt

En

d

Research

Market

DevelopmentR&D programme

Figure 1: Since several years, a lot of research on VIP has been done. In the HiPTI-programme someremaining but important questions have to be answered. Furthermore the development of HiPTI systems willbe initialised and the market stimulated.

1. There are still some technical questions concerning the quality of VIP. These questions needto be answered, to convince the customers of this technology. Customers are thecompanies, which develop HiPTI systems, planners, which use these systems and buildingowners.

2. SME’s have to be informed about the new technology and supported in their activities todevelop HiPTI systems.

At the end of the programme, in all participating countries:

• Some companies developed HiPTI systems, which are available on the market.

• The advantages of HiPTI systems are proven by demonstration projects.

• The market starts growing.

• Not yet involved companies begin their own developments of HiPTI systems.



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Interesting ApplicationsToday and probably in the near future, HiPTI is specifically more expensive than conventionalinsulation materials, that means you pay more for the same U-Value. In the case of VIP comparedto fibre board, the difference is about 200 to 300%. As long as this disadvantage continues, weshould use VIP for applications, where the advantage of saved space is worth the higher insulationprice. This means, where space is

• expensive and/or

• not available.

In buildings this situation can be found when you want to

• improve U-Values (retrofit)

• reach very low U-Values (low energy houses)

Building envelope HVAC components

timber-frame construction (low energy houses) storage tank (hot/cold)

metal façade (cassette) cooling and freezing appliance

façade: inside/outside tube

panel heating/cooling (floor, wall, ceiling) duct

flat roof, terrace

ceiling (basement)

cold-storage cell and house

sandwich element

door

frame enlargement

window frame

blind window

sliding shutter case

window shutter

radiator niche



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Figure 2: Some interesting applications for HiPTI systems.

Leading IdeaInvolving all participants of the market to ensure, that the needs and possibilities of these partiesare taken into consideration:

• producers of high performance insulation (VIP)

• companies, which want to develop HiPTI systems

• planners, who use systems (innovative and well-known architects, engineers)

• important building owners (government)

All these partners should work together from the beginning of the Annex activities. Planners andbuilding owners will also act as opinion leaders.

Wall (insideand outside)

Door

Terrace andflat roof

Sliding shuttercase

Floor heating

Boiler



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IEA and ECBCSThe project will be carried out under an Implementing Agreement of the International EnergyAgency.

International Energy Agency• autonomous agency linked with the Organisation for Economic Co-operation and Development

(OECD)

• 25 Member countries

• based in Paris

• objectives- joint measures to meet oil supply emergencies

- share energy information

- co-ordinate their energy policies

- co-operate in the development of rational energy programmes

Implementing AgreementIEA has a technology and R&D collaboration programme which facilitates co-operation among IEAMember and non-Member countries to develop new and improved energy technologies andintroduce them into the market.Activities are set up under Implementing Agreements which provide the legal mechanism forestablishing the commitments of the Contracting Parties (countries) and the management structureto guide the activity.There are 40 current Implementing Agreements in five groups:

• Information Centres and Modelling- Energy and Environmental Information Centres (EETIC)

- Energy Technology Data Exchange (ETDE)

- …

• Fossil Fuels- Greenhouse Gas R&D Programme

- Clean Coal Sciences

- …

• Renewable Energy- Bioenergy

- Hydropower

- …

• Energy End-Use- Advanced Fuel Cells

- Heat Pumping Technologies

- Energy in Buildings and Community Systems (ECBCS)



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The HiPTI-Project is taking place under the ECBCS Implementing Agreement as Annex 39(39th project under this Implementing Agreement).

Chairman: Mr Richard Karney (USA)

Vice Chairman: Dr Jorn Brunsell (Norway)

Contracting Parties are 21 countries and the CEC:Australia; Belgium; Canada; CEC; Denmark; Finland; France; Germany; Greece; Israel; Italy;Japan; Netherlands; New Zealand; Norway; Poland; Portugal; Sweden; Switzerland; Turkey;UK, USA.

Standards in a IEA R&D programme

• The Executive Committee usually designates an Operating Agent for each task who isresponsible for management of the collaboration and who provides infrastructure as needed.

• Contracting Parties bear their own expenses and have exclusive rights to the results.

• Annexes usually specify arrangements for handling and protection of information andintellectual property, and provide arrangements for commercial exploitation and distribution ofbenefits.

Organization of the programmeThe work in the programme will be done in three subtasks:

A Basic concepts and materials

Improve existing HiPTI insulation panels to reliable products for building applications.

Necessary properties

- heat conductivity < 15 mW/(mK) as an average over lifetime

- longevity (depending on application: 15 to >50 years)

- easy handling of insulation (for integration in HiPTI system)

B Application and systems development

Develop HiPTI systems based on high performance insulation together with partners from industryand the planning sector.

• building envelope

• HVAC components

C Demonstration / Information dissemination

Realize demonstration projects together with well-known architects and important building owners.

• prove advantages / know still existing problems

• convince opinion leaders

• stimulate the market

• motivate new developments



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Proposed management structure of Annex 39

Operating AgentResponsible for the management of the Annex:

• definition of the general objectives together with the Subtask Leaders

• organizes workshops, seminars and conferences

• provides semi-annually reports to the Executive Committee

• provide to the Executive Committee a final report

D:\E+P\IEA\Referate\[Ref_WS01.xls]Managment

IEA ECBCS ExCo

Operating Agent

Subtask Leader A Subtask Leader B Subtask Leader C

Research Partners (public and private)

National Project Leader 1

National Project Leader 2

National Project Leader n

Figure 3: The overall management structure in Annex 39.

Subtask LeadersResponsible for the management of a Subtask:

• definition of the subtask in accordance with the Annex objectives

• organizes and manages the work (work plan and time schedule)

• avoids duplication of activities within the Annex but also with other projects

• organizes meetings for the Subtask partners

• reports at least semi-annually to the Operating Agent

• provide summary on the work carried out in the Subtask



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National Project LeadersResponsible for the management of the national activities:

• definition of the national activities in accordance with the Subtask Leaders

• funding of the national activities

• in Subtask B and C:- management of the national activities

- reports at least semi-annually to the Subtask Leaders

Results• HiPTI products available on the market

• guide for companies (potential producers of HiPTI systems)

• web-site with all relevant information and contacts

• (industry association for HiPTI in buildings formed)

Work plan

Start: January 2001End: December 2004

Preparation Phase(January2001 - August 2001)

• Workshop- discuss / determine Annex objectives

- discuss / determine methods and time schedule

- assign work packages (provisional)

- assign management functions (Subtask Leaders and National Project Leaders)

• Form up project team

• Review: ‘What do we (need to) know?’

• Definition and funding of national projects

Subtask A - Basic concepts and materials(January 2000- February 2004)• Properties of available HiPTI (VIP)

• Concepts to improve properties

• Prototypes manufacturing and testing

• Support the development activities in Subtask B



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Subtask B - Applications and systems development(September 2000 - April 2004)

• Evaluation of target applications

• Description of system properties and requirements on the insulation

• Product development

Subtask C - Demonstration and information dissemination(January 2001 - December 2004)

• Objectives (type of buildings and involved partners)

• Find objects / owners and feasibility study

• Realisation

• Technical evaluation

• Information dissemination

GANNT CHART (draft 11.1.01)High Performance Thermal Insulation

ECBCS Annex 39Responsible 2001 2002 2003 2004

Task 1 2 3 4 5 6 7 8 9 # # # 1 2 3 4 5 6 7 8 9 # # # 1 2 3 4 5 6 7 8 9 # # # 1 2 3 4 5 6 7 8 9 # # #0 Preparation Phase 0.1 Workshop in Zurich ✰

0.2 Form up project team (incl. Architects) NPL (SL, OA)0.3 Review: "What do we (need to) know?" (state of the art) SL1/2 (OA)0.4 Definition and funding of national projects NPL (SL, OA)0.5 Kick-off meeting OA ✰

1 Basic Concepts and Materials (Insulation) SL11.1 Properties of available HiPTI’s ✬

1.2 Determine deviations to the specifications (see ST2)1.3 Report on available products ✰

1.4 Concepts to improve properties ✬

1.5 Prototypes manufacturing and testing ✬

1.6 Provisional report on ST1 ✬ ✰

1.7 Questions arising during product development1.8 Final report on ST1

2 Application and System Development (Insulated systems) SL2 / NPL2.1 Eval. of target applications (building elements and HVAC comp.) ✬

2.2 Description of system properties and requirements on the insulation2.3 Report on system specifications ✬

2.4 Product development2.41 Simple applications ✬

2.42 Complex applications ✬

2.5 Report on ST2 (Documentation of products) ✬ ✰

3 Demonstration and Information Dissemination SL3 / NPL3.1 Objectives (type of buildings and involved partners) ✬

3.2 Find objects / owners and feasibility study ✬

3.3 Report on planned demo projects 3.4 Information dissemination ✬

3.5 Planification ✬

3.6 Realisation ✬

3.7 Technical evaluation3.8 Final report ✰

Milestones OAReview: "What do we (need to) know?" (state of the art)Report on available productsProvisional report on ST1Report on ST2Final report

H:\IEA\Konzept\[HiPTI_Gannt_v03.xls]Termine

GlossarOA: Operating AgentSL: Subtask LeaderNPL: National Project LeaderST: Subtask✰: Annex meeting (all partners)✬: Workshop (partners of the subtask and possibly OA)



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Workshop on High Performance Thermal Insulation Systems inBuildings - (HiPTI) Vacuum Insulated Products (VIP)

ProgrammeTuesday, January 23, 2001, EMPA

8.30 Opening of workshop secretariat

9.00 Welcome and workshop introductionProposed goal, project structure, organisation and timeschedule

Markus Erb (E+P)

9.20 Subtask ABasic concepts and materialsIssues to be investigated and possible researchapproaches

Dr. J. Caps (ZAE)

9.40 Subtask BApplication and system developmentPreferred application area for VIPs, economic andapplicable solutions

Markus Erb (E+P)

10.00 Subtask CDemonstrationHiPTI installations in participating countries

Documentation, information and disseminationStrategies to address opinion leaders, clients andmanufacturers

Prof. A. Binz (FHBB)

11.00 Working groupsDiscussion of subtasks A , B

Working groups

14.00 Working groupsContinuation of Subtask discussion of subtasks A, Band starting discussions for Subtask C

Working groups

16.00 Coffee break

16.20 Preparation of working group summaries Working groups

17.00 Closure first day



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Wednesday, January 24, 2001, EMPA

9.00 Presentation of workshop resultsGeneral discussion of Subtask A – C proposals

Session Leaders

11.00 Decision process, action item list, future procedureand dates

Prof. Dr. HanspeterEicher (E+P)

12.00 End of workshop



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INTERNATIONAL ENERGY AGENCY

Energy Conservation in Buildings and Community Systems Programme

High Performance Thermal Insulation(HiPTI)

Annex draft

15.2.2001



84

1 INTRODUCTION 85

1.1 THE MEANING OF HIGH PERFORMANCE THERMAL INSULATION 851.2 RECENT DEVELOPMENTS IN THE CONSTRUCTION SECTOR 851.3 HIGH PERFORMANCE THERMAL INSULATION 85

2 AIMS 86

2.1 BASIC CONCEPTS AND MATERIALS 862.2 APPLICATION AND SYSTEM DEVELOPMENT 862.3 DEMONSTRATION AND INFORMATION DISSEMINATION 86

3 MEANS 86

3.1 SUBTASKS 863.1.1 SUBTASK A: BASIC CONCEPTS AND MATERIALS 863.1.2 SUBTASK B: APPLICATION AND SYSTEM DEVELOPMENT 873.1.3 SUBTASK C: DEMONSTRATION AND INFORMATION DISSEMINATION 87

3.2 MANAGEMENT TEAM/SUBTASK LEADERS 88

4 RESULTS / END PRODUCTS 88

4.1 SUBTASK A 884.2 SUBTASK B 884.3 SUBTASK C 84

5 ANNEX BENEFICIARIES 88

6 TIME SCHEDULE 89

7 SPECIFIC OBLIGATIONS AND RESPONSIBILITIES OF THE PARTICIPANTS 89

8 SPECIFIC OBLIGATIONS AND RESPONSIBILITIES OF THE OPERATING AGENT 89

9 FUNDING 90

10 OPERATING AGENT 90

11 INFORMATION AND INTELLECTUAL PROPERTY 90

12 PARTICIPANTS 92

13 APPENDIX 92



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1 Introduction

1.1 The Meaning of High Performance Thermal Insulation

A significant part of end energy used in western countries is for heating and hot water production.The amount of energy required depends largely on the thermal insulation.

Efficient thermal insulation is a key issue for reducing CO2 emissions.

There are two ways of obtaining improved thermal insulation:

• Increasing the thickness of the insulation. A method which has been used for the last 20 yearsbut which has various disadvantages, for example the cost of construction, the loss of space,the lower available space for renting

• Improving the thermal insulation properties by reducing the heat transfer coefficient of theinsulation material

The second approach could allow new construction details, easier application in building retrofitand energy efficient appliances (hot water tanks, refrigerators) if the insulation thickness couldeffectively be reduced.

1.2 Recent developments in the construction sector Over the last 20 years there have been important developments in the construction sector:

• The construction industry has a need for attractive, practical and feasible insulation techniquesfor wall, roof and floor construction. The insulation standard has shifted from 1 W/(m2K) to 0.3W/(m2K), and is today moving, in progression towards 0.2 and 0.15 W/(m2K). Such insulationstandard became a prerequisite for sustainable housing, passive houses or advanced retrofit.With this standards an insulation thickness of more than 20 cm in thickness is needed. In newbuildings this problem can be solved to a certain degree. But when renovating existingbuildings it has become obvious, how unsatisfactory these 15 to 20 cm insulation layers are interms of the lack of space.

• The U-values of glazing systems have shifted, thanks to the use of IR-reflective layers andspecial gas fillings from 3.0 W/(m2K) to 0.4 to 0.8 W/(m2K). On the one hand this has massivelyaffected the energy consumption of the building and on the other hand it has had, mainlyduring the last five years, a massive influence on the architecture, where the glassed façadesbecame an important element.

1.3 High Performance Thermal InsulationThe need for more efficient insulation and the availability of improved insulation materials hasincreased the interest of the construction industry for High Performance Insulation Systems (HiPTI)which are 2 to 5 times thinner than conventional insulation systems.DefinitionsHiPTI High Performance Thermal Insulations are insulation materials or systems which have

mean effective λ value smaller than 15 mW/(mK) throughout their life span.VIP Vacuum Insulation Panels are HiPTI which are evacuated to a technical vacuum in order to

further improve the thermal resistance. They normally allow a λ value smaller than5 mW/(m·K)



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2 Aims The main aim of this Annex is to develop components for buildings based on HiPTI. We call themHiPTI systems (façade element, door, hot water storage, etc.). The successful developmentsshould lead to competitive products which are available on the market. This aim will be achieved inthree Subtasks:

2.1 Basic concepts and materials

• Existing products, mainly VIP, will be analysed and their properties optimised in the way, thatthey meet the requirements of the HiPTI systems in which they will be applied.

• New concepts for HiPTI materials and systems will be examined and evaluated. Suitableconcepts will be demonstrated as prototypes.

• Measurement standards concerning product declaration and quality monitoring procedures willbe developed.

2.2 Application and system developmentSupport companies which want to develop HiPTI systems for the building envelope and HVACcomponents. The support will consist in informing potential companies about HiPTI, form suitablegroups for each development project, provide theoretical and practical information (simulation andtesting of systems).

2.3 Demonstration and information disseminationRealize demonstration projects together with well-known architects and important building owners.

• Lessons learned from the demonstration projects will be collected and used for furtherimprovement of the materials and systems.

• Insulation specialists will be trained on site for the correct use of HiPTI's

• Information material will be distributed to increase the interest of construction companies andclients.

3 Means

3.1 SubtasksWork will be grouped into three subtasks Subtask A Basic concepts and materials Subtask B Application and system development Subtask C Demonstration and information dissemination

3.1.1 Subtask A: Basic concepts and materials

Improving existing solutions Existing solutions (VIP) should be investigated to improve their technical, economical andecological characteristics e.g. thermal conductivity, physical and chemical properties, longevity,reliability, production cost, recycling and grey energy content. This includes the basic materials(microporous materials, films and foils, getter materials) and the VIP-production processes(preparation and shape of microporous materials, wrapping and sealing techniques).



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Further questions to be dealt with in Subtask A will also arise when subtasks B and C are handled,e.g. there might arise the need for VIP with special shapes (bent panels, panels with holes).Therefore the subtasks must overlap chronologically.

Standards

To improve confidence of customers in the new technology, standards have to be developed.These standards confine type and measurement of product properties which are important for thecustomer. Furthermore a method has to be developed which is suitable to determine the quality of built-in VIP(on site).

New concepts

In this section research will be carried with the aim to improve some properties of VIP which arecrucial for certain applications. The focus will be on developing HiPTI consisting of relatively smallunits so that a small scale injury of the VIP envelope (screws, nails) does not lead to a vacuumloss in a large panel. An another task will be to develop HiPTI for tubes which basically requires aflexible system.

3.1.2 Subtask B: Application and system development

The aim is to develop suitable insulation systems for the most important applications, which shouldbe available on the market after termination of the Annex. The first step is to evaluate the applications in building, which would gain distinct advantages fromHiPTI's in terms of energy and/or cost saving. Co-operation between insulation materials producers, insulation system suppliers, planners andbuilding contractors should lead to specific product profiles. These will include technical as well aseconomic characteristics. Special attention should be paid to the development of products, whichresemble conventional solutions as closely as possible in their application. In this way they canexpect to be well received on the market. In addition new HiPTI systems for critical parts of the building shell and for technical systemsshould be developed as future technologies for houses with very low energy consumption (e.g.passive houses).

3.1.3 Subtask C: Demonstration and information dissemination

The aims of this part of the Annex are field testing and market introduction of the new products. Incollaboration with large, innovative building contractors, architects and opinion leaders (e.g.governmental agencies) demonstration projects will be implemented. The following objectives should be achieved by the end of the Annex:

• In the important markets for HiPTI (e.g. internal insulation, floor heating, flat roof renovation,hot water equipment, façade cladding systems, doors and so on).

• 10 leading building contractors from the participating countries should have performed andevaluated at least one large project with HiPTI, when renovating housing stock.

• 10 recognised and leading architects should have carried out at least one renovation or newconstruction project with HiPTI.

• National opinion leaders should have been informed about the HiPTI products and know aboutthe demonstration projects.



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• HiPTI products and systems should be available according to market conditions in theparticipating countries.

• An industry association for HiPTI in Buildings should be formed, to keep internationalcollaboration going after termination of the Annex.

3.2 Management Team/Subtask LeadersThe management team consists of the Operating Agent, and the Leaders of Subtasks A, B and C.For Subtasks B and C each participating country has an own co-ordinator.

4 Results / End Products

4.1 Subtask AThe work carried out in Subtask A should provide an overview of the basic concepts and materialssuitable for producing HiPTI.Above all, vacuum insulations should have been improved to meet the requirements of buildingapplications.Standards concerning product declaration and quality monitoring procedures are available.Research publications will document the state of the art, available materials and concepts andrecommendations for the use of the different systems in the construction sector.

4.2 Subtask BHiPTI systems, whose properties have been tested and optimised as regards to usability and lifespan are available on the market and can be supplied to customers with standard marketperformance guarantees.A guideline for the application of new HiPTI insulated constructions and components will bepublished.

4.3 Subtask CEvery participating country should have implemented HiPTI demonstration covering an area of atleast 1'000 m2. Findings from these projects will be documented and used to improve systems andapplications.Important building contractors, investors and architects should have a basic knowledge of theopportunities offered by HiPTI technologies and how to make use of them.Opinion Leaders in the construction business should be well informed about the properties of HiPTIand are able to inform customers about their usability.Information regarding durability over a period of at least three years should be available. Selecteddurability tests will be constantly performed after Annex termination.

5 Annex BeneficiariesIn general, the activities in this Annex should contribute to the reduction of energy use and CO2

emissions in the construction sector. It should improve the applicability of HiPTI technologies anddemonstrate the benefits to users and opinion leaders in all participating countries. It should allowto attract enough interest to create a market for such systems. On the basis of the experiencegained it should lead to further R&D activities and product development, also for other applicationsthan in the construction sector.



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6 Time ScheduleThe Annex planning phase will take approximately one year. The duration of the Annex, after theplanning phase, will be three years.During the Annex planning phase, the activities for Subtask A (e.g. R&D review, search forindustrial partners) can be started.The table in the Appendix demonstrates the time schedule for the different Annex phase activities.

7 Specific Obligations and Responsibilities of the ParticipantsParticipants in the Annex will be physicists, engineers, representatives of the industry, buildingconstructors, architects and investors.In addition to the obligations enumerated above:

• Participants will be expected to provide such information as exists in their own countries tofacilitate the work of the country dealing with a designated topic;

• Each participant will be expected to act as a primary reviewer for the output of one of the otherParticipants. This responsibility for detailed review will ensure that the work produced will notreflect any particular national bias, but properly represents consensus of the Participants in theAnnex.

8 Specific Obligations and Responsibilities of the Operating AgentIn addition to the obligations previously mentioned the Operating Agent shall:

a. Prepare the detailed Programme of Work for the Annex in consultation with the SubtaskLeaders and the Participants and submit the Programme of Work and a time schedule forapproval to the Executive Committee;

b. Be responsible for the overall management of the Annex. This includes overall co-ordination,liaison between the Subtask and communications with the Executive committee of IEA,providing information and implementing actions required;

c. Chair each of the full Annex meetings and be responsible for setting each agenda. Assistanceat each meeting will be provided by the Participant from the nation hosting the meeting;

d. Prepare and distribute the results mentioned in paragraph 5 above;

e. Prepare joint assessments of research, development and demonstration priorities whendesired or necessary;

f. At the request of the Executive Committee, organise workshops, seminars, conferences andother meetings;

g. Propose and maintain a methodology and a format for the submission of information which iscollected by the Participants as described in paragraph 4 above;

h. Provide, at least semi-annually, periodic reports to the Executive Committee on the progressand the results of the work performed under the Programme of Work;

i. Provide an annual technical report to the Participants in the Annex;

j. Provide to the Executive committee, within twelve months after completion of all work under theAnnex, a final report for its approval and transmittal to the Agency;



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k. In co-ordination with the Participants, use its best efforts to avoid duplication with activities ofother related programmes and projects implemented by or under the auspices of the Agency orby other competent bodies;

l. Provide the Participants with the necessary guidelines for the work to be carried out in theSubtasks, for reports to be made and information to be distributed;

m. Perform such additional services and actions as may be decided by the Executive Committee,acting by unanimity.

9 FundingThe minimum commitment of each country for Subtasks A, B and C will be 4 person-years in total.It is expected that Subtask A will be carried out by a limited number of participants (about four) withan overall input of about 8 person-years. In the Subtasks B and C all participants are involved.Funding includes working costs, travelling costs and eventual overhead costs. Additional costsmay result from material and equipment needed for R&D and demonstration.For the Operating Agent, additional funding shall allow for an extra 4 months per year of Annexactivities, including the attendance of 2 ExCo-meetings per year. For the Leaders of the 3Subtasks funding shall allow for an extra 2 months per year of Annex activities.Each Participant shall bear the costs resulting from its work under this Annex.

10 Operating AgentThe Operating Agent for the Annex shall be Dr. Eicher+Pauli AG, Switzerland.

11 Information and Intellectual Property

a. Executive Committee's Powers. The publication, distribution, handling, protection andownership of information and intellectual property arising form this Annex shall be determinedby the Executive Committee, acting by unanimity, in conformity with the Agreement.

b. Right to Publish. Subject only to copyright restrictions, the Participants shall have the right topublish all information provided to or rising from this Annex, except proprietary information.

c. Proprietary Information. The Participants and the Operating Agent shall take all necessarymeasures in accordance with this paragraph, the laws of their respective countries andinternational law to protect proprietary information provided to or arising from this Annex. Forthe purposes of this Annex, proprietary information shall mean information of a confidentialnature such as trade secrets and know-how (e.g. computer programs, design procedures andtechniques, chemical composition of materials, or manufacturing methods, processes ortreatments) which is appropriately marked, provided such information:

• Is not generally known or publicly available form other sources;

• Has not previously been made available by the owner to others without obligationconcerning its confidentiality;

• Is not already in the possession of the recipient Participant without obligation concerningits confidentiality.



91

It shall be the responsibility of each Participant supplying proprietary information, and of theOperating Agent for appraising proprietary information, to identify the information as such andto ensure that it is appropriately marked.

d. Production of Relevant Information by Governments. The Operating Agent should encouragethe governments of all Agency Participating Countries to make available or to identify to theOperating Agent all published or otherwise freely available information known to them that isrelevant to the Annex.

e. Production of Available Information by Participants. Each Participant agrees to provide to theOperating Agent all previously existing information, and information developed independentlyof the Annex, which is needed by the Operating Agent to carry out its functions in this Annexand which is freely at the disposal of the participant and the transmission of which is notsubject to any contractual and/or legal limitations.

• If no substantial cost is incurred by the Participant in making such information available, atno charge to the Annex therefore.

• If substantial costs must be incurred by the Participant to make such information available,such charges to the Annex shall be agreed between the Operating Agent and theParticipant with the approval of the Executive Committee.

f. Use of Confidential Information. If a Participant has access to confidential information whichwould be useful to the Operating Agent in conducting studies, assessments, analyses, orevaluations, such information may be communicated to the Operating Agent but shall notbecome part of reports or other documentation, nor be communicated to the other Participantsexcept as may be agreed between the Operating Agent and the Participant which suppliessuch information.

g. Acquisition of Information for the Annex. Each Participant shall inform the Operating Agent ofInformation that can be of value to the Annex, but which is not freely available, and theParticipant shall endeavour to make the information available to the Annex under reasonableconditions, in which even the Executive Committee may, acting unanimity, decide to acquiresuch information.

h. Reports of Work Performed Under the Annex. The Operating Agent shall provide reports of allthe work performed under the Annex and the results thereof, including studies, assessments,analyses, evaluations and other documentation, but excluding proprietary information , inaccordance with paragraph (c) hereof.

i. Copyright. The Operating Agent may take appropriate measures necessary to protect thecopyright of the material generated under this Annex. Copyrights obtained shall be the propertyof the Operating Agent for the benefit of the Participants provided, however, that Participantsmay reproduce and distribute such material, but shall not publish it with a view to profit, exceptas otherwise directed by the Executive Committee.

j. Authors. Each Participant will, without prejudice to any rights of authors under its national laws,take necessary steps to provide the co-operation from its authors required to carry out theprovision of this paragraph. Each Participant will assume the responsibility to pay award orcompensation required to be paid to its employees according to the laws of its country.



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12 Participants

The Contracting Parties which are Participants in this Annex are the following:

(Provisional, paragraph will be finalized later)

Austria

Belgium

Canada

Denmark

France

Germany

Italy

Netherlands

Sweden

Switzerland

U.K

13 Appendix• Time Schedule

Time scheduleHigh Performance Thermal Insulation

ECBCS Annex 39Responsible 2001 2002 2003 2004

Task 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 120 Preparation Phase0.1 Workshop in Zurich ✰

0.2 Form up project team NPL (SL, OA)0.3 Review on VIP (state of the art) SL1/2 (OA)0.4 Definition and funding of national projects NPL (SL, OA) ✬ ✰

A Basic Concepts and Materials (Insulation) SL1A.1 Properties of available HiPTI’s ✬

A.2 Determine deviations to the specifications (see ST2)A.3 Report on available products ✰

A.4 Concepts to improve properties ✬

A.5 Prototyps manufacturing and testing ✬

A.6 Report on ST1 ✬ ✰

B Application and System Development (HiPTI systems) SL2 / NPLB.1 Define target applications (building envelope and HVAC comp.) ✬

B.2 Description of system properties and requirements on the insulationB.3 Report on system specifications ✬

B.4 Product developmentB.41 Simple applications ✬

B.42 Complex applications ✬

B.5 Report on ST2 (Documentation of products) ✬ ✰

C Demonstration and Information Dissemination SL3 / NPLC.1 Objectives (typ of buildings and involved partners) ✬

C.2 Find objects / owners and feasability study ✬

C.3 Report on planned demo projectsC.4 Planification ✬

C.5 Realisation ✬ ✰

C.6 Technical evaluationC.7 Information dissemination ✬

C.8 Final report ✰

Milestones OAReview on VIP (state of the art)Report on available productsReport on ST1Report on ST2Final report

GlossarOA: Operating AgentSL: Subtask LeaderNPL: National Project LeaderST: Subtask

Duration of SubtaskDuration of activityDuration of preperatory activity

✰: Annex meeting (all partners)✬: Workshop (partners of the subtask and possibly OA)93



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Preliminary Study on High Performance Thermal Insulation Materialswith Gastight Porosity

M. Damani, U. Vogt, Th. GrauleEMPA Dübendorf, Switzerland

In recent years a lot of work has been done in order to achieve better thermal insulation materials.The focus was set on microporous materials like fumed silica products [1, 2] and also on silicaaerogel products [3, 4]. These materials show very low thermal conductivity (< 0,02 W/(mÂ.��ZKLFKcan be even more decreased if the materials are evacuated. For instance, so called VacuumInsulation Panels, which consist of evacuated fumed silica, have a thermal conductivity as low as0,004 W/(mÂ.��%XW�DOO�WKHVH�SURGXFWV�KDYH�LQ�FRPPRQ�WKDW�WKH\�QHHG�D�YDFXXP�WLJKW�HQYHORSHand are therefore susceptible to damage during transport and installation on the building site. Theyalso cannot be machined or cut to size.

It has been shown that there is a market for slim insulation materials which can be made 5 to 10times thinner than conventional insulation as a result of their significant lower thermal conductivity.The object of this investigation was to perform a literature research and to study possibilities for themanufacturing of gastight inorganic materials with very low thermal conductivity to overcome theproblems discussed above.

A closer look was taken on cellular or foamed glass which seems to be an ideal candidatefor an inorganic gastight insulation material. About twenty independent publications onfoamed glass developments were found [5]. Little work has been done in order todecrease the thermal conductivity of the material, most of the researchers concentrated onprocessing routes and the use of different raw materials, mainly the recycling of wasteproducts. The lowest thermal conductivity reported for foamed glass is approx. 0,04W/(mÂ.��>�@�

Special attention is paid to composite materials as only such materials are generallyconsidered for insulation purposes. It has to be noticed that a porous materials isconsidered a composite as it consists of two phases: a solid matrix material and a gas.The thermal conductivity depends on the amount and arrangement of the phases. In caseof foamed glass the two phases are glass and pore gas. The glass represents thecontinuous phase whereas the major phase, the pore gas, is discontinuous (fig.1).



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In such a material the pores decrease the thermal conductivity nearly in proportion to thefraction of the porosity [7, 8]. The conductivity can be decreased by controlling the porecontent, e.g. it becomes lower if the pores contain a gas with very low conductivity or ifthey are evacuated. As radiation also plays a role if a material is transparent, theseglasses usually contain opacifiers. Heat transfer through radiation across pores is low forsmall pores at low temperatures. The contribution from radiation becomes higher if thepores are large (a few millimetres and above), in particular if they contain a gas which istransparent for radiation or if they are evacuated [9, 10].

Figure 1: Simplified schematic structure of a foamed glass (section). The glass (dark) is the continuousphase; the major phase (pores, light) is discontinuous.

The microporous insulation materials have a very low thermal conductivity (0,02 W/(mÂ.��not evacuated). This results from the fact that the pore phase is continuous and there areusually only point contacts between the solid particles, an idealised schematic structure ofsuch a material is shown in figure 2a and b. The resulting conductivity is therefore largelydetermined by the effective conductivity of the pore phase which is usually a gas, e.g. air.The conductivity of any gas is lower than that of any solid material. Furthermore, theconductivity of such materials is dependent on the gas pressure and also the pore size.This means it can be further decreased by evacuating the pore spaces and/or reducing thepore sizes by using smaller grain sizes [8, 9].

Aerogels are also open-pore structures with minimal solid-solid contacts (3 nm accordingto literature [11]; figure 2 a and c), therefore, the same principle for thermal conductivityapplies in these type of materials. Whereas for fumed silica products opacifiers are usuallyadded to suppress radiation this is not necessary for silica aerogels as they are naturallyopaque for infrared radiation at low temperatures (below 100°C).



97

b)

a) c)

Figure 2: Strongly simplified schematic structure of microporous insulation materials:

a) 3-dimensional pore network, solid particles have only point contacts (for both fumed silica products andaerogels);

b) 2-dimensional section through a powder compact (fumed silica);

c) 2-dimensional section through an aerogel.Up to now very little effort has been put into improving closed pore materials like foamedglass in respect to decrease its thermal conductivity. An approach could be made bydesigning new structures with gastight porosity but also by improving existing materials.Mathematical calculations show that it is possible to achieve a thermal conductivity as lowas the conductivity of microporous materials by reducing the fraction of solid matrixmaterial in a glass foam to a minimum. A further decrease in thermal conductivity and anincrease in mechanical stability could be achieved by designing a composite material witha major discontinuous phase which has a very low conductivity, e.g. an aerogel, and aninorganic minor phase which forms only a very fine three-dimensional network around themajor phase but still provides sufficient strength and gastightness. It should also beconsidered to improve foamed glass by optimising its cell structure and the appropriatechoice of pore gas and evacuating the pores, respectively.

References

1. Eicher H, Hochleistungs-Wärmedämmsysteme, Dr. Eicher + Pauli AG, Fachhochschulebeider Basel, im Auftrag des Bundesamtes für Energie, Liestal, 1997

2. Eicher H, Erb M, Binz A, Moosmann A, Hochleistungs-Wärmedämmung HLWD,Schlussbericht, Dr. Eicher + Pauli AG, Fachhochschule beider Basel, im Auftrag desBundesamtes für Energie, Liestal, 2000

3. Newman B, Lu L, Thermal Insulation, especially Pipe Insulation, and Manufacture ofthe Thermal Insulation, Patent EP 841308 19971111, USA, 1998

4. Reiss M, Aerogele – Wärmedämmstoffe der Zukunft, In DKV-Tagungsbericht, 23 Jg.,



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Vol. 2/1, pp. 215-224, 1997

5. Damani M, Vorabklärung zur Herstellung hochisolierender Keramik-Dämmstoffe,Zwischenbericht, EMPA Dübendorf, 2000

6. Physical and Thermal Properties of Foamglass Insulation, Fa. Pittsburgh CorningCorp., http:\\www.foamglassinsulation.com/c3.html, Dezember 2000

7. Francl J, Kingery WD, Thermal Conductivity: IX, Experimental Investigation of Effect ofPorosity on Thermal Conductivity, J. Am. Ceram. Soc., 37, pp. 99-107, 1954

8. Kingery WD, Bowen HK, Uhlmann DR, Introduction to Ceramics, John Wiley & Sons,New York, pp.1032, 1976

9. Schulle W, Melzer D, Wärmedämmung bei hohen Temperaturen - Möglichkeitenmikroporöser Baustoffe, Stahl und Eisen, 119, pp. 55-58, 1999

10. Russell HW, Principles of Heat Flow in Porous Insulators, J. Am. Ceram. Soc., 17-18,pp. 1-5, 1934/35

11. Fricke J, Thermal Transport in Porous Superinsulations, In Aerogels, SpringerProceedings in Physics 6, ed. J Fricke, Springer Verlag, pp. 94-103, 1986



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Flexible Pipes with High Performance Thermal Insulation

R. WeberEMPA DuebendorfSection Energy Systems/Building EquipmentÜberlandstrasse 1296000 Dübendorf

IntroductionThe highest losses on energy don't emerge with the production of heat or cold, but with distributionof it. Conventional High Performance Thermal Insulation (HiPTI) – pipes are difficult in use andneed a lot of space. This study shall show, if new forms of pipes are possible and what the mainproblems of them will be.

Description of the productIt should be possible to solve some problemsof conventional pipes with flexible vacuuminsulated pipes. This new concept is plannedwith cheaper plastic pipes instead of steel-pipes insulated with welded chromium steel.The plastic pipe shall be wrapped with avacuum bandage, which has predeterminedcutting places. Therefore, these pipes can bedelivered on construction side as rolls and canbe cut into specified lengths on place by acraftman. Because of the flexibility of the pipe,you won't have big problems caused bydilatation.

The bandage is formed with micro porousmaterial, and enveloped with two gastightfilms. To avoid coldbridges, two bandagesshall be wrapped in a staggered way (Fig. 1).As protection against mechanical injures, aprotective coat comes over the outer bandage.

The predetermined cutting places are a resultfrom welding the two films. Therefore thebandage is divided in chambers. Eachchamber is evacuated. That means, if theenvelope of the bandage get hurt, not thewhole pipe is vacuumless.

)LJ��Fig. 1



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Goals of the actual studyThe study shall deliver a list of problems and questions that must be solved:

• Materials questions (which film, which filling material, how much vacuum etc.).

• Technology questions (how to wrap the bandage, geometrical questions of the chamber, howto apply the pipe).

• Try to produce a sample and make first tests.

• Which industrial partners are interested in a development project.

• How a future development project has to be formulated.

Already known research topicsThe gastight film is delicate in usage. This film consists of different layers. The gastight layer maybe aluminium or in newer cases siliziumoxid. If the film is folded often or strong, the gastight layermay break. Unfortunately, this fact isn't easy visible without technical help (e.g. microscope). Butlong time vacuum isn't possible with a defect in the gastight layer. One topic will be, to get lessdelicate films.Until now, it isn't very clear, were the most leackages of air into the vacuumed chambers comesfrom. If the pinholes lying in the film are responsible, further development has to be done in filmtechnology. But we think, more problems result in welding the film. Especially if you have the microporous material as powder, you will always have some impurity in the weldseam. With thathandicap, seams may be leaky. One topic will be, to explore how to weld without impurities.Depending on used materials, today films have a thermal conductivity in length which are about 50

to 3000 times higher than theconductivity of the filling material. Thedanger to create coldbridges withfilms is given. The question will be,how large respectively how small thechambers can be made withoutnoticeable losses. During the runningstudy, we want to compute how smallchambers may be, without giving upthe demand that we get a highinsulation product. (Fig. 2)

To wind stiff bandages around a small pipe may cause unpredictable folding. That means, air willbe enclosed and this will produce additional cold bridges. Perhaps we have to cluster the bandageon the inner side. But then the question arises, how many clusters do we need and how is itpossible to produce such a clustered bandage.The stiffness of the bandage comes from the vacuum. Perhaps with krypton as gas inflation, thestiffness can be circumvented. But it is not yet examined, how the mix of penetrating air withkrypton will effect the thermal conductivity of the micro porous material.At least, how can we guarantee, that the embedded insulation won't loose the good characteristicnext 25 years?

ConclusionA lot of questions we have are also interesting for other High Performance Thermal Insulationprojects. A lot of them were unique to our specific problem. I'm looking forward, to have a gooddiscussion and I'm hoping to find some answers ore at least to get some ideas.

Fig. 2.



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Evaluation of modern insulation systems by simulation methodes

Univ.Prof.Dr.Jürgen DREYER, Dipl.Ing. Thomas Bednar, Dipl.Ing. Clemens HechtUniversity of Technology Vienna , Institute of Building Materials,Building Physics and Fire ProtectionKarlsplatz 13/206, A-1040 [email protected]

Modern insulation systems are loads by several climatic and using effects, which can induce a da-maging of the materials. There are mechanical loads by weight, wind, push, ground moving andaltering, thermal loads by thermal expansion and tension and hygric loads by wetting processes,grow of mould, salt crystallisation, hygric tension etc. The knowledge about this processes de-pendent on using and climatic conditions can help to avoid these problems.Many existing buildings are in bad condition referring to their thermal insulation. That is a result oflow heat technical requirements in the past and also caused by damage and weathering of thebuilding stock. To decrease the heat loss of buildings with facades being worth to be kept is it ne-cessary to find adequate solutions.For an improvement of the heat insulation an very exactly analysing and a better understanding ofthe properties of the building materials are necessary. Modelling and simulation of the thermal andhygric behaviour can be a good method to evaluate new building construction referring to durabilityand life cycle.In the paper are given some example of investigation new systems to find out the possibilities ofapplication.

IntroductionFor the preservation of outer facades of buildings which belong to the cultural heritage it is notpossible to fix an insulation board at the outside. Therefor it is necessary to develop interior insula-tion system, which have to be adapted with the old building stock.Good properties for this aim has insulation material with a ability of water transfer. If the old buil-ding has a wooden framework construction the conditions are more severe then in the case of anoutside insulation layer. The characteristic of calcium silicate leaded to the development of a spe-cial lining board, a alternative system to protective and renovation render systems.A special interior insulation system is developed with a integrated heating zone in the board. In thisway a modern heating system can used, higher surface temperature produces a better humancomfort, the heating energy can decreased and the moisture load on the exterior wall can be de-creased.Exterior insulation systems with a transparent heat insulation layer are well known. This systemsare very expensive and the thermal load in summer is often to high. These problems have beenthe reasons to investigate an transparent render or an exterior insulation system based on a com-bination of an insulation render system and a transparent insulation system. In this way it is possi-ble to get an insulation render system with a partial transparency.



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Inside InsulationIn the following chapters the traditional performance evaluation method is compared with the re-sults based on simulation of the heat and moisture transfer and the results for different inside in-sulation are shown [1],[2]. By using the standard calculation methods no information about therelative humidity and the temperature in the structure is presented to the user and the only pa-rameter, which leads to the performance evaluation is the ratio of the condensing to the evaporat-ing amount of water. In this way one would prefer the variants with high diffusion resistance as thesystems with no moisture problems.Build in moisture during the renovation time or additional water from driving rain, which is one ofthe main problems for unrendered wooden framework structures [2] is neglected. To account forbuild in moisture and to get a better inside into the moisture behaviour of the construction one canuse simulation tools for the heat and moisture transfer processes in constructions. The modelspresented in [5] are capable of calculating the moisture transfer in the vapour and the liquid phaseand in this way the behaviour of materials with a high capillary water transport ability can be inves-tigated with them.The moisture content of the structure with an inside insulation has been calculated for 10 years.Over this period the weekly average of the temperature and the relative humidity at the interfacebetween the wooden part and the inside insulation has been stored. The results for the applicationof mineral wool as interior insulation are presented in Figure 1. The data presented in figure 1clearly shows the high moisture contents during the cold season which exceed the limiting curvefor 16 weeks of exposure and even for 8 weeks of exposure. An additional vapour barrier elimi-nates the condensation of water, but as seen in figure 2, during the first year nearly no drying ofwater has happened because of the great vapour resistance to the inside.

Figure 1: Weekly average relative humidity against weeklyaverage temperature at the inside of the wooden part for aninside insulation made out of mineral wool without (Var. 1)and with (Var. 2) a vapour barrier. The limiting conditions forthe development of the initial stages of mould growth areshown as lines for an exposure time of 2, 4, 8 and 16 weeks[Viitannen 1996].

If an expanded polystyrene is used for interior insulation the drying process of the construction inthe first year is very slow. During a lot of weeks the average moisture condition is above the limit-ing curves.A rather different behaviour shows an interior insulation with a high capillary force. calcium silicatehas the ability to transport water by capillary forces. In this way, if the relative humidity in the insideinsulation increases, the moisture content due to sorption of water increases too, and water istransported with capillary forces back to the room. Therefor compatible hygric condition can achie-ved with this material in the construction. The drying of the construction is fast because of the lowvapour resistance of calcium silicate. As one can see only during the weeks with very low outdoor

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temperatures a relative humidity of 80% is exceeded in the wooden part. Because of the low tem-perature during those weeks mould growth is not initiated

Inside insulation board with a high salt storage capacity for moisture and salt loaded wallsFor the maintenance of moisture and salt destroyed walls are special measures for a continuesustainable redevelopment necessary. Different systems for repair of damages at this time arepossible. The most and relative successful used system are protective and renovation render.In the latest years the department of building physics at the Technical University of Vienna devel-oped an indoor lining board for moisture- and salt damaged buildings [8]. The developed liningboard based on calcium silicate. It is a alternative product to protective and renovation render sys-tems.The lining board is developed for moisture and salt loaded walls. Is the wall destroyed only be-cause of moisture, the calcium silicate lining board can be applicated without treating. There are 3possibilities for the treatment of calcium silicate lining Boards for using them on moisture and saltloaded walls:1. complete hydrophobisation,2. treatment of the surface,3. reduce the capillary moisture transport from the backside through backside treatmentWith variant 1 the biggest reduction of salt entry is possible. An entry of the salt solvent into thelining board is to be possible, like the protection and renovation render. The crystallisation takesplace in the capillaries. Most of the capillaries are hydrophobic, that’s why only a minimal mass ofthe solvent can penetrate into the board.Most investigations takes place about surface treatment, possibility 2. The treatment is optimisedbetween maximum capillary moisture and salt transport into the lining board and a minimum ofdestruction because of salt crystallisation. The salt crystallisation in our investigations takes placebetween the treated and non treated parts of the lining board.The following figure 2 shows the behaviour of the system due to condensation and evaporation inthe wall after different treatments of the lining board by using as inside insulation.

Figure 2: Moisture content inside a wall by using differ-ent lining boards (types of treatment), without rain load

For the support of our laboratory tests we have a practical one at Schloß Zell a.d. Pram in LowerAustria. Different variations of the developed slabs are in long time analysis and under continuoscontrol of our department. This test will be used to find a optimised performance at the buildingsite.

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Inside Insulation System with a Internal Wall Heating SystemTo lower additional the heat losses one can use an inside insulation system. The negative effect ofsuch n inside insulation is, depending on the outer render and the used insulation material, an inc-reased moisture load of the construction. The reason is, that in winter the main part of the const-ruction will be cooler and the moisture remain and in the summer the moisture evaporate and mo-ves deeper in the construction. With a special air conditioned zone it is possible to decrease the

moisture load. The developed system consist of an insulati-on layer, an air conditioned zone and a finishing board asthe new surface. Furthermore it is possible to use the zonefor heating. With the insulation layer the thermal resistanceof the construction can be increased and with the conditio-ned zone the moisture load on the exterior wall can be dec-reased. Figure 3 shows a sketch of the construction whichhas been developed.

Figure 3: Interior insulation with an integrated heating system

The thermal performance of such buildings was investigatedto know the possibility to decrease the energy use for hea-ting and the moisture load by condensation. For this aim theenergy use of a whole building was calculated in considera-

tion of all components of heat loss, like transmission through walls, windows, roof and ground andventilation, and of all gains, like radiation and internal gains. Only by a simulation of the annualenergy balance of a building the effect of a measure of reconstruction can evaluated in the rightway. The energy use of a single family house was calculated. The result of the calculation of theannual energy use of this house for the initial state, that is the state without a inside insulation anda integrated heating system, and of the final state, with buffer zone and inside insulation, is seen infigure 4.

Figure 4: Annual energy use of a singlefamily house before and after a applicationof an inside insulation and a heating zonein the wall to exterior. Average monthlyexternal temperature and required tem-perature of heating zone, integrated in thewall

In the figure is seen, that a temperature in the buffer zone from twenty until thirty degree Celsius isnecessary. This energy supply correspond the energy loss of the wall, floor, ceiling and windows.The temperature of the surface of the wall is in this case between twenty and twenty-five centigra-de Celsius. The reduction of heating energy is approximately 30 percents.

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This effect can increase if one use better insulation for floor, ceiling and windows and a higherthermal resistance for the additional inside insulation. In this case a little improvement was chosen,that the variation of the thermal conditions of the walls is not so great. The temperature and vapourpressure distribution show interesting behaviour. The temperature of the bricks wall lays between0°C and 13 °C, that is comparable with the state before use of a inside insulation. If a internalmoisture content below 75 % is used, no condensation problem will exist in the wall. By the highertemperature in the buffer zone a condensation can avoid without a vapour moisture barrier. Therisk of condensation in the wall construction for the average monthly climatic conditions seems tobe very low, because an internal moisture content of more then seventy percents are necessary forthis effect. By the help of the temperature in the heating zone a risk can avoid in the whole timeperiod of a year.

Exterior insulation render system with solar radiation transmissionExterior insulation systems with a transparent heat insulation layer are well known for some years.This systems are very expensive and the thermal load in summer is often to high. These problemshave been the reasons to develop an exterior insulation system based on a combination of an in-sulation render system and a transparent insulation system. To mount the heat insulation systemat the outside of a wall a light plastic framework with transparent elements is fixed and the space inbetween the framework is filled with an insulation render system. In this way it is possible to get aninsulation render system with a high thickness and a partial transparency.To determine the energy saving effect of this system the method for calculating the space heatingrequirements for residential buildings according to EN 832 has been used. This standard calculati-on method uses the transmission heat loss of all construction elements from the internal to theexternal environment, the ventilation losses, the usable internal heat gains and the usable solargains through windows, sunspaces and opaque elements with transparent insulation. Through toutilisation factors it is not possible to overestimate the impact of solar energy on the space hea-ting requirement.The thermal performance of an building with a transparent render system at the exterior walls wasinvestigated to know the possibility to decrease the energy use for heating. For this aim the energyuse of a whole building was calculated in consideration of all components of heat loss, like trans-mission through walls, windows, roof and ground and ventilation, and of all gains, like radiation andinternal gains. The investigated single house has99 m² floor and roof, 91 m² opak wall area and 19 m² window area. The heat transmission coeffi-cients of the building elements are 0,5 m²*K/W ( floor ), 2 W/m²*K (window), 0,8 W/m²*K (ceiling)and 0,8 W/m²*K (wall). To improve the thermal quality an additional inside insulation is used with athermal resistance R= 0,5 m²*K/W.

Figure 5: Reduction of energy consumptionfor a whole building by using a transparentinsulation render.

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Only by a simulation of the annual energy balance of a building the effect of a measure of re-construction can evaluated in the right way. The energy use of a single family house with the cha-racteristics given in table 1 of building elements was calculated.In Figure 5 the results are given for several degrees of transparency of the external insulation sys-tem.

References[1] Fechner, H., Häupl, P., Martin, R., Neue, J., Petzold, H., Thermische Sanierung von Fach-

werkbauten mittels Innendämmung, Dresdner Bauklimatische Hefte, Heft 5, 1998

[2] Künzel H., Erhaltung von Fachwerkfassaden durch Ausfachung mit neuen Baustoffen, 1.Internationaler Kongress zur Bauwerkserhaltung, Berlin, Februar 1992

[3] Künzel, H.M., Verfahren zur ein- und zweidimensionalen Berechnung des gekoppelten Wär-me- und Feuchtetransports in Bauteilen mit einfachen Kennwerten, Dissertation UniversitätStuttgart, 1994

[4] Künzel, H.M., Kießl, K., Drying of brick walls after impregnation, Bauinstandsetzen, 2 (1996)H. 2, pp. 87-100

[5] Künzel, H.M. (Hrsg.), Praktische Beurteilung des Feuchteverhaltens von Bauteilen durchmoderne Rechenverfahren, WTA Schriftenreihe, Heft 18, Aedificatio Verlag, 1999

[6] Viitannen, H., Factors affecting the development of mould and brown rot decay in woodenmaterial and wooden sturctures, Thesis, University of Agricultural Science, Uppsala 1996

[7] Recherche über Sanierputze (nicht veröffentlicht), Datenbestand: ca. 20 Veröffentlichungen,2 Dissertationen, WTA - Schriftenreihe Heft 7 „Sanierputzsysteme“ und Heft 14 „Anwendungvon Sanierputzen in der baulichen Denkmalpflege“, ca. 25 Herstellerunterlagen

[8] WTA-Merkblatt 2-2-91 „Sanierputzsysteme“, 1992

[9] J. Dreyer, C.Hecht: Entwicklung einer Innendämmplatte für salz- und nässegeschädigteBauteile; WTA-Schriftenreihe. Heft 20 (1999), S. 187-197



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Development of vacuum insulation panel with stainless steel envelope

P. HoogendoornLEVEL energy technologyPanterlaan 20NL-5691 GD Son,

Co–operating in a European Craft project, a group of SME's and research groups willdevelop a prototype production line for vacuum insulation panels with rectangularstainless steel envelopes. Objective of the development is to acquire and test thetechnologies needed for the production line, fit for a broad range of temperatures, fillermaterials and sizes. The demands are a fast, robust and flexible production methodleading to a competitive product. The concept with a stainless steel envelope is chosenbecause of the possibility of producing hermetically closed panels with a life expectancy >50 years with low thermal bridges, appropriate for temperatures up to 450 °C. The straightedges make interconnection of panels possible

IntroductionIn 1997 a European Craft project was successfully finished: development of evacuated superinsulation panels with a tenfold increase of performance. The project was aimed at experimentallytesting the methods needed for an all-round panel with a life expectancy fit for the building sector.During the project the list of demands was set up, complying with the specific demands of theparticipants. A common demand was a lifetime of > 50 years with an end pressure of 10 Pa for atemperature up to 80 °C for a 1 m2 panel. The envelope has to be suited to apply several fillermaterials and to be interconnected as part of a construction system.Potential envelope materials and joining methods have been investigated and tested with respectto permeability, outgasing and thermal conductivity. Promising filler materials have been testedfor mechanical stability, outgasing and thermal conductivity characteristics. The tests resulted in achoice of a concept for a prototype panel with a stainless steel envelope, some prototype panelshave been produced.In August 2000 a group of SME's and R&D performers started a follow up Craft project:Development of methods for a prototype production line for vacuum insulation panels.

ObjectivesThe main objective of the project is to research and develop methods for the constituent parts ofa prototype production line for vacuum insulation panels, leading to a fast and flexible productionmethod for a competitive product. The objectives are:



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• 33 Euro/m2 based on a pilot production capacity of 45,000 m2/year

• a tenfold increase of thermal insulation value; 2 < λ < 5 mWm-1K-1

• flexibility of panel size up to 1,2 x 1 m2

• construction system for mutual panel connection with low thermal bridges

• new developed laser welding method with laser weld speeds of > 0,1 ms-1

• evacuating time < 500 s, approval measurement within 200 s• total reduction of ageing by preventing moisture absorption• life expectancy > 50 years at internal pressure < 10 Pa• improved fire resistance of panels up to 60 min.• clean handling due to hermetically closed envelope, causing no health hazards• completely recyclable at end of life

Research approachThe research focuses on 4 main aspects:

Filler material: different materials will be used: PUR, XPS and glass fibresFor the broad application of vacuum insulation panels, fibre filler, polyurethane and polystyrenewill be used. The materials will have different application fields. The insulation material must havean open structure to make evacuation to 1 Pa possible. The main fibre and foam properties willbe defined, such as solid conduction, cell dimensions, maximum allowable internal pressure, andthe possible need of evacuation ducts. Treatment methods such as time and temperature oftempering and flushing with dry nitrogen to remove water will be determined. The need of gettermaterial will be investigated.

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Evacuation method: a fast method is developed to make a high production capacitypossibleIn order to obtain a fast production method the evacuation time of 1 m2 of vacuum insulationpanel should be < 500 s. Possible operations to fill the envelope with fibre/foam board followed bya vacuum pumping step will be investigated. Methods to decrease the pumping time will bedetermined such as the use of evacuation ducts, the use of getters as after pump, and flushingwith dry gases to remove water.



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Envelope: the envelope should be hermetically closed with low thermal bridgesFeasible geometry's of the stainless steel envelope parts will be compared for several purposesand temperature ranges. Related to the degree of ductility, deformation, laser welding properties,and costs aspects.A mutual connection system for vacuum panels with minimised cold bridges will be designed forapplication in, a.o., cold stores, fleece facades and buildings.Different welding principles will be coupled to the preferred envelope geometry's. The penetrationweld geometry will be tested in detail, as a function of foil thickness laser pulse frequency,velocity, laser power and positioning accuracy.A model will be developed to calculate the average thermal conductivity, stresses inside thepanel and deformations. The foil thickness is an important parameter for the cold bridges.

Measurement method: a method is developed to give an indication of the thermal conduc-tivity within 200 s after productionMethods for testing the thermal/vacuum quality of a panel just after production will be developed.For checking the thermal insulation value of a super insulation panel, innovative measurementtechniques have to be used. The thermal conductivity value is around λ = 3 mW/(mÂ.��PXFKlower than the thermal conductivity of the surrounding air (λ = 26 mW/(mÂ.��OHDGLQJ�WR�D�GLIILcultmeasurement. The measurement is needed for a go/no go decision just after production of apanel.After the research phase a prototype production line will be designed, built and tested. Panels willbe produced and tested. Prototype applications will be designed, built and tested.

The stainless steel conceptCommonly, development of vacuum insulation is characterised by a filler material of micropowder or foam (XPS or PUR), wrapped in plastic foils, mostly with a laminated aluminium layer.The foils are sealed, forming flaps at the edges of the panel. The seam welded flaps preventinterconnection of panels, increasing the edge losses. Because the diffusion of gases increasesexponentially with temperature, applications above 20 °C are hardly possible. During this projecta prototype production line will be developed for panels with different kinds of filler material, and alaser welded rectangular stainless steel envelope. This concept is chosen for the followingreasons:

Edge losses

Because of the low λ value of the filler material, and the relative high λ value of the envelopematerial, the quality of the vacuum insulation panels will be considerably influenced by theenvelope material and geometry. In the stainless steel concept we aim at edges of 25 µm, withstraight edges. The straight edges make close interconnections possible, the gap between twopanels will be in the order of millimetres. This results in a low cold bridge, there are no flapswhich will increase the cold bridge.

An aluminium laminate of 7µm aluminium (λ = 237 mW/(mÂ.�� P� SRO\HVWHU� �λ = 0,15mW/(mÂ.��DQG��P�SRO\HWK\OHQH��λ = 1,05 mW/(mÂ.��KDV�DSSUR[LPDWHO\�WKH�VDPH�HIIHFW�RQthe cold bridge as 115 µm stainless steel (λ = 15 mW/(mÂ.�� 1RW� RQO\� WKH� DYHUDJH� KHDWconductivity of a vacuum insulation panel is increased by the edge losses, it also causes coldspots. For determining the influence of the thickness of the edge, a simple 2-dimensional finiteelement model is written. Fig. 2b shows some results of varying the thickness of the stainlesssteel edge foil. Fig 2a shows the base geometry and parameters for the calculation. A thicknessof 25 µm results in an average heat conductivity of 0,0026 mW/(mÂ.�� LQcreasing the heat



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conductivity with 30 %, the cold spot is 18 °C. An aluminium laminate would result in an averageheat conductivity of 0,0037 Wm-1K-1, increasing the heat conductivity with 85 %, the cold spot is14,5 °C. Decreasing the dimensions of the panel results in higher average heat conductivity's andthe same cold spots.

500

20

0,2

edge foil λ = 0,002 W/(mK)

T = 20 °C α = 7 W/(m2K)

T = 0 °C α = 10 W/(m2K)

λ = 15 W/(mK)

B

B

B

BB

BB

BB

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12

13

14

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16

17

18

0 25 50 75 100 125 150 175 200 225 250

[Wm-1K-1] [°C]

thickness edge [µm]

B heat conductivity J cold spot

Figure 2: a) base geometry for calculation, b) results of calculation

Life expectancyFor the selected filler material the gas pressure has to stay below 10 Pa. The internal pressureincreases by desorbing of gases from filler material and envelope and by gases permeatingthrough the envelope. To obtain a life time of 50 years the pressure increase has to be < 6 10

-

9 Pa s-1 (or 0,2 Pa year-1). Some continuous tests were done on prototype panels, using a

vacovac tube device, measuring the slip of a rotating ball in a tube. The vacovac tube allows forcontinuous measurement in a closed panel (using a vacuum sluice), see fig. 3a.

Figure 3: a) evacuated prototype test panel b) pressure rise of panels

The measurements of panel 5, 6 and 10 over a period of more than 2 years are shown in fig. 3b.Panel 5 shows the desired behaviour; desorption of the absorbed gases in the first 50 days and

BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB B B

B B BBBB B

JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ

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HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH H H H H H

HHH H

0

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then a constant influx of 0,12 Pa year-1. Panel 10 has been less good degassed, but shows a leakof only 0,11 Pa year

-1. Panel 6 is well degassed, but has a small leak in a corner that has been

covered with an epoxy resin, causing a leak of 0,47 Pa year-1.

Due to the laser welding the casing is hermetically closed. Fig. 3 gives examples of results oflaser welding of thin foils.

Figure 4: a) cross section of laser weld between two perpendicular foils of 200 µmb) penetration weld of a foil of 50 µm to 100 µm

Temperature rangePanels with glass fibre as filling material can be used for temperatures up to 450 °C, increasingthe application field. Panels with polyurethane and polystyrene as filler material will be cheaperbut can be used for temperatures of respectively 120 and 80 °C. The envelope is hermeticallyclosed, the panel is completely enclosed by a metal with a very low diffusivity for gases. Anincrease in temperature does not lead to a considerable increase in diffusion of gases throughthe envelope.

Interconnection of panelsThe straight edges allow interconnection of panels, which allows building of constructions, withlow thermal bridges. The panels do not have flaps which would cause a space between twopanels, or increase the thickness of the edge, when folded alongside the edge.

Other

• The concept of the steel envelope and glass fibre as filling material allows to make the panelswitchable with respect to thermal conductivity by a factor of > 50. A metal hydride can beused, when heated it will emit hydrogen, causing an increase of thermal conductivity. Thehydrogen will be absorbed when the metal hydride is not heated, resulting in a super isolatedpanel.

• for several applications stainless steel is required for hygienically reasons (e.g. cold storage).

• stainless steel is a better material for protection, compared to aluminium or plastic foil.

• no finishing material has to be used

• no corrosion is expected



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ConclusionsStainless steel has some advantages over common used envelope materials for vacuuminsulation panels.

• Considering a panel of 1 m2, the cold bridges are small (30 %) due to the thin edge foils (25µm), the average heat conductivity is low.

• Due to the hermetic closed envelope, the leak rate is small, the pressure increase is < 0,2 Payear-1 the life expectancy is > 50 years.

• Panels can be used for temperatures till 450 °C, increasing the application field

• The panel promises to be cheap (33 Euro/m2), when produced in mass production

High Performance Thermal Insulation (HiPTI) – Vacuum Insulated Products (VIP), EMPA,January 22–24, 2001

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Workshop on HiPTI (Annex 39)

Proceedings of the workshop

Preface 114

1. Conclusions of the working groups 115

1.1. Subtask A 115

1.1.1. Subject

1.1.2. Discussed topics

1.2. Subtask B 116

1.2.1. Subject


1.3. Subtask C 119

1.3.1 Subject


2. Next steps 121

2.1. National projects

2.2. Subtask Leaders

3. Appendix 122


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Preface

The Swiss activities in the area of new insulation materials for buildings lead to the conclusion thatthis topic should be looked at on a international basis. The reasons are to share the necessaryexpenses for R&D activities, to involve the important producers of the needed materials, which areinternational companies, and to inform and stimulate the market for such products on a largescale.

The proposal for such a programme was adopted by the Executive Committee of the IEA Imple-menting Agreement 'Energy in Buildings and Community Systems' (ECBCS) in summer 2000 asAnnex 39.

The conference and workshop held in Zurich on January 22 - 24, 2001 aimed at defining moreprecisely the content of the Annex, find the suitable partners for the work to be done and set up anaction item list, leading to the official start of the Annex in September 2001.


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1. Conclusions of the working groups

1.1. Subtask ABasic concepts and materials

1.1.1. Subject

In Subtask A High Performance Thermal Insulation should be developed which meets the needsof HiPTI systems, i.e. components of building envelope and HVAC systems.

In case of vacuum insulations, Subtask A will deal with production of VIP as a whole. This includesevacuation and sealing of panels.


Objectives

Test and improve existing materials

Research on alternative concepts

Main tasks

Database

Collection of data for possible materials:

- core materials: foams, fibres, powders

- envelope: films, foils, steel envelope

- getter materials

- application based definition of sytem properties in coordination with subtask B

Improvement of envelope

- better high barrier films and foils

- sealing and packing technology

- reliable and fast test methods

Core material

- powders: lower density, lower conductivity

- high allowable gas pressure

- mechanical properties

Quality tests of vacuum panels


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- quality standards

- long life time, high reliability

- ageing methods (function of temperature, mechanical stress, humidity)

- internal gas sensor

- environmental aspects (energy input, recycling, emission)

Standardization of testing methods

- quality standards

- gas and moisture transmission

- mechanical properties

- formats

Models for performance of panels

- calculation methods for performance evaluation

1.2. Subtask BApplication and system development

1.2.1. Subject

In Subtask B insulation systems for buildings and insulated components (envelope and HVAC)based on HiPTI will be developed and tested.


Where should we use HiPTI systems

Where place is scarce / expensive

Where temperature difference is high

Where the vacuum insulation can easily be replaced (depending on expectancy of VIP lifespan)

Where VIP is well protected (plaster, metal) against getting punctured by screws, nails etc.

The interesting applications mentioned during the workshop are listed bellow:


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Building envelope HVAC components

timber-frame construction (low energy houses) solar collectors

external cladding systems storage tank (hot/cold)

façade renovation system (external/internal) cooling and freezing appliance

panel heating/cooling (floor, wall, ceiling) tube (district heating)

flat roof, terrace duct

ceiling (basement) heating systems

cold-storage chamber energy storage container

door

frame enlargement

window frame

roller shutter box

radiator niche

There are easier and more complicate applications. The group could not agree on starting with justthe easier applications since: ’The more problems you face the more you learn’.

Crucial questions

expectancy of lifetime

guarantee by the producer (probability of failure): an on site monitoring procedure has to be devel-oped.

moisture problems

Standards

Producers of VIP and potential producers of HiPTI systems think, that a process of standardizationhas to be started. The needed standards comprise:

Quality of VIP: physical properties have to be measured and declared (guaranteed) in a standard-ized manner (Subtask A). These standards will improve confidence in VIP products.

Formats of VIP: As in the case of conventional products, standard panel formats have to be de-fined.

Intellectual property

Certain applications will be developed by different companies. These companies must have anadvantage from participating in the Annex, so they may not be willing to declare their whole knowhow. To reduce these problems, it may be a good solution, that specific applications are justdeveloped by one company per country.


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Central Services (shared problems)

A catalogue of shared problems has to be worked out and answered in common, as a basis for allcompanies, which develop HiPTI systems within the Annex.

Projects

In some countries there are already HiPTI projects running or in preparation. Others expressed atleast their interest for certain applications or questions:

• Switzerland

- running projects: façade renovation system (external/internal), flat roof, terrace, door,boiler.

- projects in preparation: tubes/ducts, foam cover for VIP, testing/calculations on HiPTI sys-tems.

• Germany: has developed VIPs for various applications and is currently running different dem-onstration projects in buildings in Bavaria.

• France: development of façade cladding systems in preparation. The system will be testedunder extreme conditions. France could provide this testing infrastructure for other projects.

• Germany: Is currently running different demonstration projects in Bavaria (building envelope).

• Netherlands: Is interested in façade renovation systems and solar collectors.

• Austria: Could probably work on common questions in the area of building physics (moisture).

• Canada: May be interested in hot water equipment.


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1.3. Subtask CDemonstration and information dissemination

1.3.1. Subject

In Subtask C successful developments of Subtask B will be applied in suitable buildings. Informa-tion from all Subtasks has to be disseminated.


"Vision" of demonstration projects

Three types of demonstration projects with different goals and requirements:

Demonstration Test application

Integral project Building renewalNew office building

Single elements Solar collectorFaçadeetc.

Pipe-, ductworkInterior wall-insulationetc.

Characteristics Integral convincing conceptDemonstration of feasibilityand reliability

"High risk" conceptExperiences and feedbackto product optimisation

Scope conditions, requirements and aspects to be considered

Professionalism: professional quality standards of products and project (no do-it-yourself or Dis-neyland)

Cost effectiveness: Believable demonstration of future economic competitiveness.

Awareness of role and duty of the demonstration part of the project:

- Neutral information (promotion)

- Better products for the consumer

Focus on opinion leading groups: architects, big building owners, consumer?

Use positive side effects and technology trends:

- High-tech aspects

- Architectural and design options


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Further procedure

Precise definition of demonstration task profile

Fix priorities, dates, milestones

Get in touch with

- VIP producer

- Element manufacturers

- Investors, building owners

- architects

Clear means and methods

- Competitions

- Subsidies

- Measurement concepts

- etc.

Get the funding


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2. Next steps

2.1. National projectsFor each present country, a coordinator was assigned (see Appendix) which is responsible for theorganisation of a national project until the definite national project coordinator is found. This meanshe will contact the necessary people to form a national project team. This team has to work out adraft of the national activities. This draft has to be sent to the Operating Agent till April 15.

Each participating country should contribute at least to Subtask B and C. The expected commit-ment of each country is described in the Annex text.

2.2. Subtask LeaderDuring the workshop some suggestions concerning the three Subtask Leaders were made (seeAppendix). Further suggestions can be made to the Operating Agent till April 15. The decision onthe definite Subtask Leaders has to be taken till the next meeting which probably will be on May 22in Italy.

Persons who are interested in becoming Subtask Leader should be independent of any productrelevant to the Annex.


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3. Appendix

Project schedule

Date Action Responsability24.01.2001 Workshop, selction of National Coordinators and

Subtask leaders

15.02.2001 Workshop report M. Erb

15.04.2001 Drafts of national projects must be delivered toOperating Agent

National Coordinators

22.05.2001 Meeting of Operating Agent, Subtask Leaders andNational Coordinators in Rom in order tocoordinate national projects

M. Erb (general)P. Manini (local)

30.05.2001 Intermediate report to ExCo and workshopparticipants

M. Erb

15.06.2001 Information of ExCo Members at the ExComeeting

M. Zimmermann and M.Erb

15.09.2001 Definite text of national projects and finance plan National Coordinators

24./25.9. 01 Meeting national teams in Würzbürg ZAE/M. Erb

15.11.2001 ExCo meeting. Official project start M. Zimmermann

National project coordinators

Austria Dreyer, JürgenBelgium Hens, Hugo?Canada Kumaran, KumarDenmark M. Zimmermann makes another contactFrance Quenard, DanielGermany Caps, Roland / Heinemann, UlrichItaly Manini, Paolo / De CarliNetherlands Cauberg, HansSweden Jóhannesson, GudniSwitzerland Erb, MarkusU.K. M. Salmon/Earl Pereira (will be contactet by Mr. Kumaran)

G:\2000\040\Konferenz WS\Proceedings\[schedule.xls]Tabelle1



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List of Participants

Arnold Bruno, ZZ Wancor, Althardstr. 5, CH-8105 Regensdorf, [email protected]

Bertram Hans-Georg, Dr., Forschungszentrum Jülich GmbH, D-52425 Jülich, [email protected]

Bertschinger Hans, EMPA ZEN, Überlandstr. 129, CH-8600 Dübendorf, [email protected]

Binz Armin, Prof., FHBB, St. Jakobstr. 84, CH-4132 Muttenz, [email protected]

Bolliger Max, Schneider Dämmtechnik AG, Im Hölderli 26, CH-8405 Winterthur, [email protected]

Bonnebat Claude, Usinor, 1, route de St-Leu, F-60761 Montataire, [email protected]

Bugge Garn Claus, Rockwool Int., DK-2640 Hedehusene, [email protected]

Caps Roland, Dr., ZAE Bayern, Am Hubland, D-97074 Würzburg, [email protected]

Cauberg Hans, Prof., TU Delft, P.B. 480, NL-6200 AL Maastricht, [email protected]

Damani Monika, Dr., EMPA Hochleistungskeramik, Überlandstr., CH-8600 Dübendorf, [email protected]

Demharter Anton, Puren Schaumstoff GmbH, Rengoldshauserstr. 4, D-88662 Überlingen, [email protected]

Dorer Viktor, EMPA ZEN Energiesysteme, Überlandstr. 129, CH-8600 Dübendorf, [email protected]

Dreyer Jürgen, Dr., TU Wien, Karlsplatz 13, A-1040 Wien, [email protected]

Duttlinger Werner, Dr., Sto AG, Abt. VI A, Ehrenbacherstr. 1, D-79780 Stühlingen, [email protected]

Eberhard Hans, Cabot GmbH, Heisingerstr. 18, D-87437 Kempten, [email protected]

Eicher Hanspeter, Prof., Dr. Eicher+Pauli AG, Kasernenstr. 21, CH-4410 Liestal, [email protected]

Erb Markus, Dr. Eicher+Pauli AG, Kasernenstr. 21, CH-4410 Liestal, [email protected]

Erbenich Gregor, Cabot GmbH, Josef-Bautz Str. 18, D-63457 Haunau, [email protected]

Feist Wolfgang, Dr., Passivhaus Institut, Rheinstr. 44/46, D-64283 Darmstadt, [email protected]

Fierz Christian, HTA Luzern, ZIG, Technikumstr. 21, CH-6048 Horw, [email protected]

Frank Thomas, EMPA ZEN Bauphysik, Überlandstr. 129, CH-8600 Dübendorf, [email protected]

Fricke Jochen, Prof., ZAE Bayern, Am Hubland, D-97074 Würzburg, [email protected]

Furler René, Dr., ZZ Wancor, Althardstr. 5, CH-8105 Regensdorf, [email protected]

Herrmann Volker, Glas Trösch AG, Industriestr. 29, CH-4922 Bützberg, [email protected]

Hess Simon, Ernst Basler & Partner, Mühlebachstrasse 11, CH-8032 Zürich, [email protected]

Hoogendoorn Peter, Level energy technology, Panterlaan 20, NL-5691 GD Son, [email protected]

Jacobsen Sven, Covexx Films Walsrode, Postfach 1661, D-29656 Walsrode, [email protected]

Jóhannesson Gudni, Prof., KTH - Building Technology, S-10044 Stockholm, [email protected]

Kistler Rudolf, Alporit AG, Industriestr. 559, CH-5623 Boswil, [email protected]

Klein Hans, Dr., Sto Aktiengesellschaft, Ehrenbachstr., D-79780 Stuehlingen, [email protected]

Kloo Josef, Microtherm N.V., Rosenstr. 4, D-83052 Bruckmühl, [email protected]

Kumaran Kumar, NRC Canada, CA-Ottawa, [email protected]

Lefebvre Gerald, Lawson Mardon, Finkernstrasse 34, CH- 8280 Kreuzlingen, [email protected]

Loustau Jean-Pierre, TBC SARL, 25 Bd V. Hugo, parc scient. du perget, F-31770 Coloniers, [email protected]

Manini Paolo, Dr., SAES Getters, Viale Italia 77, I-20020 Lainate, [email protected]



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Mankell Kurt, Certainteed Corp., 1400 Union Meeting Rd., USA-19422 Blue Bell, [email protected]

Materna Ralf, Dr., Geberit AG, CH-8645 Jona, [email protected]

Nussbaumer Beat, Dr. Eicher+Pauli AG, Viktoriastr. 69, CH-3000 Bern 25, [email protected]

Ochs Markus, Dr., Schweizer Metallbau, CH-8908 Hedingen, [email protected]

Ortjohann Jörg, Regenerative Energietechnik, Lichtstr. 50 D-50852 Köln, [email protected]

Özkan Kubilay, IZOCAM, T-41455 Oilovasi-Febze-Kocaeli, [email protected]

Pätz Stephan, SAES Getters, Gerlosteiner Str. 1, D-50937 Koeln, [email protected]

Pötter Franz-Josef, Cabot GmbH, Josef-Bautz Str. 18, D-63457 Haunau, [email protected]

Quenard Daniel, CSTB, 24, rue Joseph Fourier, F-38400 St. Martin d'Heres, [email protected]

Randel Peter, Dr., Wacker-Chemie, Max-Schaidhauf-Strasse 25, D-87437 Kempten, [email protected]

Reber Georges, Dr. , Institut für Physik, Uni Basel, Klingelbergstr. 82, CH-4056 Basel, [email protected]

Rigacci Arnaud, Cenerg-Ensmp, Rue C. Daunesse, F-O6904 Sophia Antipolis, [email protected]

Rosai Livio, Dr., SAES Getters, Viale Italia 77, I-20020 Lainate, [email protected]

Simmler Hans, Dr., EMPA ZEN Bauphysik, Überlandstr. 129, CH-8600 Dübendorf, [email protected]

Spitznagel Eugen, ZZ Wancor, Althardstr. 5, CH-8105 Regensdorf, [email protected]

Staufert Gerhard, Dr., Sager AG, Leutwilerstr. 281, CH-5724 Dürrenäsch, [email protected]

Vogt Ulrich, Dr., EMPA Hochleistungskeramik, Überlandstr. 129, CH-8600 Dübendorf, [email protected]

Weber Robert, EMPA ZEN Energiesysteme, Überlandstr. 129, CH-8600 Dübendorf, [email protected]

Wellstein Jürg, Temas, Egnacherstr. 69, CH-9320 Frasnacht, [email protected]

Widmann Franz, Lawson Mardon , Alusingen-Platz 1, D- 78221 Singen , [email protected]

Willems Wolfgang, Dr., Thyssen Krupp Stahl, Essenerstr. 59, D-46047 Oberhausen, [email protected]

Würsten Felix, Neue Zuercher Zeitung, Falkenstrasse 11, CH - 8021 Zuerich, [email protected]

Zimmermann Mark, EMPA ZEN, Überlandstr. 129, CH-8600 Dübendorf, [email protected]

Züllig Hans-Ulrich, WFT Fassadentechnik AG, Neugrüt, CH-8570 Weinfelden, [email protected]

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